Auto merge of #125313 - matthiaskrgr:rollup-65etxv0, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - #125034 (Weekly `cargo update`)
 - #125093 (Add `fn into_raw_with_allocator` to Rc/Arc/Weak.)
 - #125282 (Never type unsafe lint improvements)
 - #125301 (fix suggestion in E0373 for !Unpin coroutines)
 - #125302 (defrost `RUST_MIN_STACK=ice rustc hello.rs`)

r? `@ghost`
`@rustbot` modify labels: rollup

18 files changed, 445 insertions, 150 deletions

diff --git a/Cargo.lock b/Cargo.lock
index ad88b1ea5a3..5afd71a4bed 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -74,11 +74,11 @@ checksum = "5c6cb57a04249c6480766f7f7cef5467412af1490f8d1e243141daddada3264f"
 
 [[package]]
 name = "ammonia"
-version = "3.3.0"
+version = "4.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "64e6d1c7838db705c9b756557ee27c384ce695a1c51a6fe528784cb1c6840170"
+checksum = "1ab99eae5ee58501ab236beb6f20f6ca39be615267b014899c89b2f0bc18a459"
 dependencies = [
- "html5ever",
+ "html5ever 0.27.0",
  "maplit",
  "once_cell",
  "tendril",
@@ -212,9 +212,9 @@ dependencies = [
 
 [[package]]
 name = "anyhow"
-version = "1.0.83"
+version = "1.0.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25bdb32cbbdce2b519a9cd7df3a678443100e265d5e25ca763b7572a5104f5f3"
+checksum = "b3d1d046238990b9cf5bcde22a3fb3584ee5cf65fb2765f454ed428c7a0063da"
 dependencies = [
  "backtrace",
 ]
@@ -257,7 +257,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -414,9 +414,9 @@ checksum = "514de17de45fdb8dc022b1a7975556c53c86f9f0aa5f534b98977b171857c2c9"
 
 [[package]]
 name = "camino"
-version = "1.1.6"
+version = "1.1.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c59e92b5a388f549b863a7bea62612c09f24c8393560709a54558a9abdfb3b9c"
+checksum = "e0ec6b951b160caa93cc0c7b209e5a3bff7aae9062213451ac99493cd844c239"
 dependencies = [
  "serde",
 ]
@@ -571,7 +571,7 @@ dependencies = [
  "anstream",
  "anstyle",
  "clap_lex",
- "strsim 0.11.1",
+ "strsim",
  "terminal_size",
 ]
 
@@ -593,7 +593,7 @@ dependencies = [
  "heck 0.5.0",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -620,7 +620,7 @@ dependencies = [
  "regex",
  "rustc_tools_util",
  "serde",
- "syn 2.0.62",
+ "syn 2.0.64",
  "tempfile",
  "termize",
  "tokio",
@@ -647,7 +647,7 @@ dependencies = [
  "clap",
  "indoc",
  "itertools 0.12.1",
- "opener",
+ "opener 0.6.1",
  "shell-escape",
  "walkdir",
 ]
@@ -730,7 +730,7 @@ dependencies = [
  "nom",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -957,9 +957,9 @@ dependencies = [
 
 [[package]]
 name = "darling"
-version = "0.20.8"
+version = "0.20.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "54e36fcd13ed84ffdfda6f5be89b31287cbb80c439841fe69e04841435464391"
+checksum = "83b2eb4d90d12bdda5ed17de686c2acb4c57914f8f921b8da7e112b5a36f3fe1"
 dependencies = [
  "darling_core",
  "darling_macro",
@@ -967,27 +967,27 @@ dependencies = [
 
 [[package]]
 name = "darling_core"
-version = "0.20.8"
+version = "0.20.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c2cf1c23a687a1feeb728783b993c4e1ad83d99f351801977dd809b48d0a70f"
+checksum = "622687fe0bac72a04e5599029151f5796111b90f1baaa9b544d807a5e31cd120"
 dependencies = [
  "fnv",
  "ident_case",
  "proc-macro2",
  "quote",
- "strsim 0.10.0",
- "syn 2.0.62",
+ "strsim",
+ "syn 2.0.64",
 ]
 
 [[package]]
 name = "darling_macro"
-version = "0.20.8"
+version = "0.20.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a668eda54683121533a393014d8692171709ff57a7d61f187b6e782719f8933f"
+checksum = "733cabb43482b1a1b53eee8583c2b9e8684d592215ea83efd305dd31bc2f0178"
 dependencies = [
  "darling_core",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -997,12 +997,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a0afaad2b26fa326569eb264b1363e8ae3357618c43982b3f285f0774ce76b69"
 
 [[package]]
+name = "dbus"
+version = "0.9.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1bb21987b9fb1613058ba3843121dd18b163b254d8a6e797e144cbac14d96d1b"
+dependencies = [
+ "libc",
+ "libdbus-sys",
+ "winapi",
+]
+
+[[package]]
 name = "declare_clippy_lint"
 version = "0.1.80"
 dependencies = [
  "itertools 0.12.1",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1043,7 +1054,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1053,7 +1064,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "206868b8242f27cecce124c19fd88157fbd0dd334df2587f36417bafbc85097b"
 dependencies = [
  "derive_builder_core",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1076,7 +1087,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1165,7 +1176,7 @@ checksum = "487585f4d0c6655fe74905e2504d8ad6908e4db67f744eb140876906c2f3175d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1189,9 +1200,9 @@ dependencies = [
 
 [[package]]
 name = "either"
-version = "1.11.0"
+version = "1.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a47c1c47d2f5964e29c61246e81db715514cd532db6b5116a25ea3c03d6780a2"
+checksum = "3dca9240753cf90908d7e4aac30f630662b02aebaa1b58a3cadabdb23385b58b"
 
 [[package]]
 name = "elasticlunr-rs"
@@ -1503,7 +1514,7 @@ checksum = "87750cf4b7a4c0625b1529e4c543c2182106e4dedc60a2a6455e00d212c489ac"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -1735,13 +1746,27 @@ checksum = "bea68cab48b8459f17cf1c944c67ddc572d272d9f2b274140f223ecb1da4a3b7"
 dependencies = [
  "log",
  "mac",
- "markup5ever",
+ "markup5ever 0.11.0",
  "proc-macro2",
  "quote",
  "syn 1.0.109",
 ]
 
 [[package]]
+name = "html5ever"
+version = "0.27.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c13771afe0e6e846f1e67d038d4cb29998a6779f93c809212e4e9c32efd244d4"
+dependencies = [
+ "log",
+ "mac",
+ "markup5ever 0.12.1",
+ "proc-macro2",
+ "quote",
+ "syn 2.0.64",
+]
+
+[[package]]
 name = "http"
 version = "0.2.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1941,7 +1966,7 @@ checksum = "d2abdd3a62551e8337af119c5899e600ca0c88ec8f23a46c60ba216c803dcf1a"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -2044,9 +2069,9 @@ dependencies = [
 
 [[package]]
 name = "instant"
-version = "0.1.12"
+version = "0.1.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7a5bbe824c507c5da5956355e86a746d82e0e1464f65d862cc5e71da70e94b2c"
+checksum = "e0242819d153cba4b4b05a5a8f2a7e9bbf97b6055b2a002b395c96b5ff3c0222"
 dependencies = [
  "cfg-if",
 ]
@@ -2198,6 +2223,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "libdbus-sys"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06085512b750d640299b79be4bad3d2fa90a9c00b1fd9e1b46364f66f0485c72"
+dependencies = [
+ "cc",
+ "pkg-config",
+]
+
+[[package]]
 name = "libffi"
 version = "3.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2258,7 +2293,7 @@ dependencies = [
 name = "linkchecker"
 version = "0.1.0"
 dependencies = [
- "html5ever",
+ "html5ever 0.26.0",
  "regex",
 ]
 
@@ -2273,9 +2308,9 @@ dependencies = [
 
 [[package]]
 name = "linux-raw-sys"
-version = "0.4.13"
+version = "0.4.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "01cda141df6706de531b6c46c3a33ecca755538219bd484262fa09410c13539c"
+checksum = "78b3ae25bc7c8c38cec158d1f2757ee79e9b3740fbc7ccf0e59e4b08d793fa89"
 
 [[package]]
 name = "litemap"
@@ -2352,6 +2387,20 @@ dependencies = [
 ]
 
 [[package]]
+name = "markup5ever"
+version = "0.12.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "16ce3abbeba692c8b8441d036ef91aea6df8da2c6b6e21c7e14d3c18e526be45"
+dependencies = [
+ "log",
+ "phf 0.11.2",
+ "phf_codegen 0.11.2",
+ "string_cache",
+ "string_cache_codegen",
+ "tendril",
+]
+
+[[package]]
 name = "matchers"
 version = "0.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2372,9 +2421,9 @@ dependencies = [
 
 [[package]]
 name = "mdbook"
-version = "0.4.37"
+version = "0.4.40"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0c33564061c3c640bed5ace7d6a2a1b65f2c64257d1ac930c15e94ed0fb561d3"
+checksum = "b45a38e19bd200220ef07c892b0157ad3d2365e5b5a267ca01ad12182491eea5"
 dependencies = [
  "ammonia",
  "anyhow",
@@ -2387,7 +2436,7 @@ dependencies = [
  "log",
  "memchr",
  "once_cell",
- "opener",
+ "opener 0.7.1",
  "pulldown-cmark 0.10.3",
  "regex",
  "serde",
@@ -2470,9 +2519,9 @@ checksum = "68354c5c6bd36d73ff3feceb05efa59b6acb7626617f4962be322a825e61f79a"
 
 [[package]]
 name = "miniz_oxide"
-version = "0.7.2"
+version = "0.7.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9d811f3e15f28568be3407c8e7fdb6514c1cda3cb30683f15b6a1a1dc4ea14a7"
+checksum = "87dfd01fe195c66b572b37921ad8803d010623c0aca821bea2302239d155cdae"
 dependencies = [
  "adler",
  "compiler_builtins",
@@ -2698,6 +2747,18 @@ dependencies = [
 ]
 
 [[package]]
+name = "opener"
+version = "0.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f8df34be653210fbe9ffaff41d3b92721c56ce82dfee58ee684f9afb5e3a90c0"
+dependencies = [
+ "bstr",
+ "dbus",
+ "normpath",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
 name = "openssl"
 version = "0.10.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -2720,7 +2781,7 @@ checksum = "a948666b637a0f465e8564c73e89d4dde00d72d4d473cc972f390fc3dcee7d9c"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -2912,7 +2973,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -4001,7 +4062,7 @@ dependencies = [
  "fluent-syntax",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "unic-langid",
 ]
 
@@ -4135,7 +4196,7 @@ version = "0.0.0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "synstructure",
 ]
 
@@ -4282,7 +4343,7 @@ version = "0.0.0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "synstructure",
 ]
 
@@ -4859,7 +4920,7 @@ version = "0.0.0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "synstructure",
 ]
 
@@ -4957,7 +5018,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -5014,9 +5075,9 @@ dependencies = [
 
 [[package]]
 name = "rustversion"
-version = "1.0.16"
+version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "092474d1a01ea8278f69e6a358998405fae5b8b963ddaeb2b0b04a128bf1dfb0"
+checksum = "955d28af4278de8121b7ebeb796b6a45735dc01436d898801014aced2773a3d6"
 
 [[package]]
 name = "ruzstd"
@@ -5125,22 +5186,22 @@ dependencies = [
 
 [[package]]
 name = "serde"
-version = "1.0.201"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "780f1cebed1629e4753a1a38a3c72d30b97ec044f0aef68cb26650a3c5cf363c"
+checksum = "226b61a0d411b2ba5ff6d7f73a476ac4f8bb900373459cd00fab8512828ba395"
 dependencies = [
  "serde_derive",
 ]
 
 [[package]]
 name = "serde_derive"
-version = "1.0.201"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5e405930b9796f1c00bee880d03fc7e0bb4b9a11afc776885ffe84320da2865"
+checksum = "6048858004bcff69094cd972ed40a32500f153bd3be9f716b2eed2e8217c4838"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -5157,9 +5218,9 @@ dependencies = [
 
 [[package]]
 name = "serde_spanned"
-version = "0.6.5"
+version = "0.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eb3622f419d1296904700073ea6cc23ad690adbd66f13ea683df73298736f0c1"
+checksum = "79e674e01f999af37c49f70a6ede167a8a60b2503e56c5599532a65baa5969a0"
 dependencies = [
  "serde",
 ]
@@ -5402,12 +5463,6 @@ dependencies = [
 
 [[package]]
 name = "strsim"
-version = "0.10.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
-
-[[package]]
-name = "strsim"
 version = "0.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
@@ -5452,9 +5507,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.62"
+version = "2.0.64"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9f660c3bfcefb88c538776b6685a0c472e3128b51e74d48793dc2a488196e8eb"
+checksum = "7ad3dee41f36859875573074334c200d1add8e4a87bb37113ebd31d926b7b11f"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -5475,7 +5530,7 @@ checksum = "c8af7666ab7b6390ab78131fb5b0fce11d6b7a6951602017c35fa82800708971"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -5626,22 +5681,22 @@ checksum = "a38c90d48152c236a3ab59271da4f4ae63d678c5d7ad6b7714d7cb9760be5e4b"
 
 [[package]]
 name = "thiserror"
-version = "1.0.60"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "579e9083ca58dd9dcf91a9923bb9054071b9ebbd800b342194c9feb0ee89fc18"
+checksum = "c546c80d6be4bc6a00c0f01730c08df82eaa7a7a61f11d656526506112cc1709"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "1.0.60"
+version = "1.0.61"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e2470041c06ec3ac1ab38d0356a6119054dedaea53e12fbefc0de730a1c08524"
+checksum = "46c3384250002a6d5af4d114f2845d37b57521033f30d5c3f46c4d70e1197533"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -5810,9 +5865,9 @@ dependencies = [
 
 [[package]]
 name = "toml_datetime"
-version = "0.6.5"
+version = "0.6.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3550f4e9685620ac18a50ed434eb3aec30db8ba93b0287467bca5826ea25baf1"
+checksum = "4badfd56924ae69bcc9039335b2e017639ce3f9b001c393c1b2d1ef846ce2cbf"
 dependencies = [
  "serde",
 ]
@@ -5862,7 +5917,7 @@ checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -6068,7 +6123,7 @@ checksum = "1ed7f4237ba393424195053097c1516bd4590dc82b84f2f97c5c69e12704555b"
 dependencies = [
  "proc-macro-hack",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "unic-langid-impl",
 ]
 
@@ -6300,7 +6355,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "wasm-bindgen-shared",
 ]
 
@@ -6334,7 +6389,7 @@ checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -6425,7 +6480,7 @@ dependencies = [
  "rayon",
  "serde",
  "serde_json",
- "syn 2.0.62",
+ "syn 2.0.64",
  "windows-metadata",
 ]
 
@@ -6657,7 +6712,7 @@ checksum = "9e6936f0cce458098a201c245a11bef556c6a0181129c7034d10d76d1ec3a2b8"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "synstructure",
 ]
 
@@ -6678,7 +6733,7 @@ checksum = "15e934569e47891f7d9411f1a451d947a60e000ab3bd24fbb970f000387d1b3b"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
@@ -6698,7 +6753,7 @@ checksum = "e6a647510471d372f2e6c2e6b7219e44d8c574d24fdc11c610a61455782f18c3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
  "synstructure",
 ]
 
@@ -6721,7 +6776,7 @@ checksum = "7b4e5997cbf58990550ef1f0e5124a05e47e1ebd33a84af25739be6031a62c20"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.62",
+ "syn 2.0.64",
 ]
 
 [[package]]
diff --git a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
index 7802825a1b8..2f1b2ce9c4c 100644
--- a/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
+++ b/compiler/rustc_borrowck/src/diagnostics/conflict_errors.rs
@@ -3343,6 +3343,10 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> {
                 } else if string.starts_with("gen") {
                     // `gen` is 3 chars long
                     Some(3)
+                } else if string.starts_with("static") {
+                    // `static` is 6 chars long
+                    // This is used for `!Unpin` coroutines
+                    Some(6)
                 } else {
                     None
                 };
diff --git a/compiler/rustc_hir_typeck/src/fallback.rs b/compiler/rustc_hir_typeck/src/fallback.rs
index e456bd7fd4a..e8533c68c79 100644
--- a/compiler/rustc_hir_typeck/src/fallback.rs
+++ b/compiler/rustc_hir_typeck/src/fallback.rs
@@ -364,41 +364,11 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
             };
 
             let mut fallback_to = |ty| {
-                let unsafe_infer_vars = unsafe_infer_vars.get_or_init(|| {
-                    let unsafe_infer_vars = compute_unsafe_infer_vars(self.root_ctxt, self.body_id);
-                    debug!(?unsafe_infer_vars);
-                    unsafe_infer_vars
-                });
-
-                let affected_unsafe_infer_vars =
-                    graph::depth_first_search_as_undirected(&coercion_graph, root_vid)
-                        .filter_map(|x| unsafe_infer_vars.get(&x).copied())
-                        .collect::<Vec<_>>();
-
-                for (hir_id, span, reason) in affected_unsafe_infer_vars {
-                    self.tcx.emit_node_span_lint(
-                        lint::builtin::NEVER_TYPE_FALLBACK_FLOWING_INTO_UNSAFE,
-                        hir_id,
-                        span,
-                        match reason {
-                            UnsafeUseReason::Call => {
-                                errors::NeverTypeFallbackFlowingIntoUnsafe::Call
-                            }
-                            UnsafeUseReason::Method => {
-                                errors::NeverTypeFallbackFlowingIntoUnsafe::Method
-                            }
-                            UnsafeUseReason::Path => {
-                                errors::NeverTypeFallbackFlowingIntoUnsafe::Path
-                            }
-                            UnsafeUseReason::UnionField => {
-                                errors::NeverTypeFallbackFlowingIntoUnsafe::UnionField
-                            }
-                            UnsafeUseReason::Deref => {
-                                errors::NeverTypeFallbackFlowingIntoUnsafe::Deref
-                            }
-                        },
-                    );
-                }
+                self.lint_never_type_fallback_flowing_into_unsafe_code(
+                    &unsafe_infer_vars,
+                    &coercion_graph,
+                    root_vid,
+                );
 
                 diverging_fallback.insert(diverging_ty, ty);
             };
@@ -464,6 +434,41 @@ impl<'tcx> FnCtxt<'_, 'tcx> {
         diverging_fallback
     }
 
+    fn lint_never_type_fallback_flowing_into_unsafe_code(
+        &self,
+        unsafe_infer_vars: &OnceCell<UnordMap<ty::TyVid, (HirId, Span, UnsafeUseReason)>>,
+        coercion_graph: &VecGraph<ty::TyVid, true>,
+        root_vid: ty::TyVid,
+    ) {
+        let unsafe_infer_vars = unsafe_infer_vars.get_or_init(|| {
+            let unsafe_infer_vars = compute_unsafe_infer_vars(self.root_ctxt, self.body_id);
+            debug!(?unsafe_infer_vars);
+            unsafe_infer_vars
+        });
+
+        let affected_unsafe_infer_vars =
+            graph::depth_first_search_as_undirected(&coercion_graph, root_vid)
+                .filter_map(|x| unsafe_infer_vars.get(&x).copied())
+                .collect::<Vec<_>>();
+
+        for (hir_id, span, reason) in affected_unsafe_infer_vars {
+            self.tcx.emit_node_span_lint(
+                lint::builtin::NEVER_TYPE_FALLBACK_FLOWING_INTO_UNSAFE,
+                hir_id,
+                span,
+                match reason {
+                    UnsafeUseReason::Call => errors::NeverTypeFallbackFlowingIntoUnsafe::Call,
+                    UnsafeUseReason::Method => errors::NeverTypeFallbackFlowingIntoUnsafe::Method,
+                    UnsafeUseReason::Path => errors::NeverTypeFallbackFlowingIntoUnsafe::Path,
+                    UnsafeUseReason::UnionField => {
+                        errors::NeverTypeFallbackFlowingIntoUnsafe::UnionField
+                    }
+                    UnsafeUseReason::Deref => errors::NeverTypeFallbackFlowingIntoUnsafe::Deref,
+                },
+            );
+        }
+    }
+
     /// Returns a graph whose nodes are (unresolved) inference variables and where
     /// an edge `?A -> ?B` indicates that the variable `?A` is coerced to `?B`.
     fn create_coercion_graph(&self) -> VecGraph<ty::TyVid, true> {
diff --git a/compiler/rustc_interface/src/interface.rs b/compiler/rustc_interface/src/interface.rs
index 55304bbbd92..d43be6cebcb 100644
--- a/compiler/rustc_interface/src/interface.rs
+++ b/compiler/rustc_interface/src/interface.rs
@@ -389,6 +389,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
     let hash_kind = config.opts.unstable_opts.src_hash_algorithm(&target);
 
     util::run_in_thread_pool_with_globals(
+        &early_dcx,
         config.opts.edition,
         config.opts.unstable_opts.threads,
         SourceMapInputs { file_loader, path_mapping, hash_kind },
diff --git a/compiler/rustc_interface/src/util.rs b/compiler/rustc_interface/src/util.rs
index ce4d3825015..ce2382b9501 100644
--- a/compiler/rustc_interface/src/util.rs
+++ b/compiler/rustc_interface/src/util.rs
@@ -51,20 +51,38 @@ pub fn add_configuration(cfg: &mut Cfg, sess: &mut Session, codegen_backend: &dy
 pub static STACK_SIZE: OnceLock<usize> = OnceLock::new();
 pub const DEFAULT_STACK_SIZE: usize = 8 * 1024 * 1024;
 
-fn init_stack_size() -> usize {
+fn init_stack_size(early_dcx: &EarlyDiagCtxt) -> usize {
     // Obey the environment setting or default
     *STACK_SIZE.get_or_init(|| {
         env::var_os("RUST_MIN_STACK")
-            .map(|os_str| os_str.to_string_lossy().into_owned())
-            // ignore if it is set to nothing
-            .filter(|s| s.trim() != "")
-            .map(|s| s.trim().parse::<usize>().unwrap())
+            .as_ref()
+            .map(|os_str| os_str.to_string_lossy())
+            // if someone finds out `export RUST_MIN_STACK=640000` isn't enough stack
+            // they might try to "unset" it by running `RUST_MIN_STACK=  rustc code.rs`
+            // this is wrong, but std would nonetheless "do what they mean", so let's do likewise
+            .filter(|s| !s.trim().is_empty())
+            // rustc is a batch program, so error early on inputs which are unlikely to be intended
+            // so no one thinks we parsed them setting `RUST_MIN_STACK="64 megabytes"`
+            // FIXME: we could accept `RUST_MIN_STACK=64MB`, perhaps?
+            .map(|s| {
+                let s = s.trim();
+                // FIXME(workingjubilee): add proper diagnostics when we factor out "pre-run" setup
+                #[allow(rustc::untranslatable_diagnostic, rustc::diagnostic_outside_of_impl)]
+                s.parse::<usize>().unwrap_or_else(|_| {
+                    let mut err = early_dcx.early_struct_fatal(format!(
+                        r#"`RUST_MIN_STACK` should be a number of bytes, but was "{s}""#,
+                    ));
+                    err.note("you can also unset `RUST_MIN_STACK` to use the default stack size");
+                    err.emit()
+                })
+            })
             // otherwise pick a consistent default
             .unwrap_or(DEFAULT_STACK_SIZE)
     })
 }
 
 fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
+    thread_stack_size: usize,
     edition: Edition,
     sm_inputs: SourceMapInputs,
     f: F,
@@ -75,7 +93,7 @@ fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
     // the parallel compiler, in particular to ensure there is no accidental
     // sharing of data between the main thread and the compilation thread
     // (which might cause problems for the parallel compiler).
-    let builder = thread::Builder::new().name("rustc".to_string()).stack_size(init_stack_size());
+    let builder = thread::Builder::new().name("rustc".to_string()).stack_size(thread_stack_size);
 
     // We build the session globals and run `f` on the spawned thread, because
     // `SessionGlobals` does not impl `Send` in the non-parallel compiler.
@@ -100,16 +118,19 @@ fn run_in_thread_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
 
 #[cfg(not(parallel_compiler))]
 pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
+    thread_builder_diag: &EarlyDiagCtxt,
     edition: Edition,
     _threads: usize,
     sm_inputs: SourceMapInputs,
     f: F,
 ) -> R {
-    run_in_thread_with_globals(edition, sm_inputs, f)
+    let thread_stack_size = init_stack_size(thread_builder_diag);
+    run_in_thread_with_globals(thread_stack_size, edition, sm_inputs, f)
 }
 
 #[cfg(parallel_compiler)]
 pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send, R: Send>(
+    thread_builder_diag: &EarlyDiagCtxt,
     edition: Edition,
     threads: usize,
     sm_inputs: SourceMapInputs,
@@ -121,10 +142,12 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
     use rustc_query_system::query::{break_query_cycles, QueryContext};
     use std::process;
 
+    let thread_stack_size = init_stack_size(thread_builder_diag);
+
     let registry = sync::Registry::new(std::num::NonZero::new(threads).unwrap());
 
     if !sync::is_dyn_thread_safe() {
-        return run_in_thread_with_globals(edition, sm_inputs, |current_gcx| {
+        return run_in_thread_with_globals(thread_stack_size, edition, sm_inputs, |current_gcx| {
             // Register the thread for use with the `WorkerLocal` type.
             registry.register();
 
@@ -167,7 +190,7 @@ pub(crate) fn run_in_thread_pool_with_globals<F: FnOnce(CurrentGcx) -> R + Send,
                 })
                 .unwrap();
         })
-        .stack_size(init_stack_size());
+        .stack_size(thread_stack_size);
 
     // We create the session globals on the main thread, then create the thread
     // pool. Upon creation, each worker thread created gets a copy of the
diff --git a/compiler/rustc_lint_defs/src/builtin.rs b/compiler/rustc_lint_defs/src/builtin.rs
index 53694545772..3b8bec887ea 100644
--- a/compiler/rustc_lint_defs/src/builtin.rs
+++ b/compiler/rustc_lint_defs/src/builtin.rs
@@ -4263,8 +4263,7 @@ declare_lint! {
     ///
     /// // where absurd is a function with the following signature
     /// // (it's sound, because `!` always marks unreachable code):
-    /// fn absurd<T>(_: !) -> T { ... }
-    // FIXME: use `core::convert::absurd` here instead, once it's merged
+    /// fn absurd<T>(never: !) -> T { ... }
     /// ```
     ///
     /// While it's convenient to be able to use non-diverging code in one of the branches (like
@@ -4321,7 +4320,12 @@ declare_lint! {
     /// [`()`]: https://doc.rust-lang.org/core/primitive.unit.html
     pub NEVER_TYPE_FALLBACK_FLOWING_INTO_UNSAFE,
     Warn,
-    "never type fallback affecting unsafe function calls"
+    "never type fallback affecting unsafe function calls",
+    @future_incompatible = FutureIncompatibleInfo {
+        reason: FutureIncompatibilityReason::FutureReleaseSemanticsChange,
+        reference: "issue #123748 <https://github.com/rust-lang/rust/issues/123748>",
+    };
+    report_in_external_macro
 }
 
 declare_lint! {
diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index dddd0603a15..875c24c28e4 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -1356,6 +1356,33 @@ impl<T: ?Sized, A: Allocator> Rc<T, A> {
         ptr
     }
 
+    /// Consumes the `Rc`, returning the wrapped pointer and allocator.
+    ///
+    /// To avoid a memory leak the pointer must be converted back to an `Rc` using
+    /// [`Rc::from_raw_in`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(allocator_api)]
+    /// use std::rc::Rc;
+    /// use std::alloc::System;
+    ///
+    /// let x = Rc::new_in("hello".to_owned(), System);
+    /// let (ptr, alloc) = Rc::into_raw_with_allocator(x);
+    /// assert_eq!(unsafe { &*ptr }, "hello");
+    /// let x = unsafe { Rc::from_raw_in(ptr, alloc) };
+    /// assert_eq!(&*x, "hello");
+    /// ```
+    #[unstable(feature = "allocator_api", issue = "32838")]
+    pub fn into_raw_with_allocator(this: Self) -> (*const T, A) {
+        let this = mem::ManuallyDrop::new(this);
+        let ptr = Self::as_ptr(&this);
+        // Safety: `this` is ManuallyDrop so the allocator will not be double-dropped
+        let alloc = unsafe { ptr::read(&this.alloc) };
+        (ptr, alloc)
+    }
+
     /// Provides a raw pointer to the data.
     ///
     /// The counts are not affected in any way and the `Rc` is not consumed. The pointer is valid
@@ -3024,11 +3051,11 @@ impl<T: ?Sized, A: Allocator> Weak<T, A> {
         result
     }
 
-    /// Consumes the `Weak<T>` and turns it into a raw pointer.
+    /// Consumes the `Weak<T>`, returning the wrapped pointer and allocator.
     ///
     /// This converts the weak pointer into a raw pointer, while still preserving the ownership of
     /// one weak reference (the weak count is not modified by this operation). It can be turned
-    /// back into the `Weak<T>` with [`from_raw`].
+    /// back into the `Weak<T>` with [`from_raw_in`].
     ///
     /// The same restrictions of accessing the target of the pointer as with
     /// [`as_ptr`] apply.
@@ -3036,27 +3063,30 @@ impl<T: ?Sized, A: Allocator> Weak<T, A> {
     /// # Examples
     ///
     /// ```
+    /// #![feature(allocator_api)]
     /// use std::rc::{Rc, Weak};
+    /// use std::alloc::System;
     ///
-    /// let strong = Rc::new("hello".to_owned());
+    /// let strong = Rc::new_in("hello".to_owned(), System);
     /// let weak = Rc::downgrade(&strong);
-    /// let raw = weak.into_raw();
+    /// let (raw, alloc) = weak.into_raw_with_allocator();
     ///
     /// assert_eq!(1, Rc::weak_count(&strong));
     /// assert_eq!("hello", unsafe { &*raw });
     ///
-    /// drop(unsafe { Weak::from_raw(raw) });
+    /// drop(unsafe { Weak::from_raw_in(raw, alloc) });
     /// assert_eq!(0, Rc::weak_count(&strong));
     /// ```
     ///
-    /// [`from_raw`]: Weak::from_raw
+    /// [`from_raw_in`]: Weak::from_raw_in
     /// [`as_ptr`]: Weak::as_ptr
     #[inline]
     #[unstable(feature = "allocator_api", issue = "32838")]
-    pub fn into_raw_and_alloc(self) -> (*const T, A) {
-        let rc = mem::ManuallyDrop::new(self);
-        let result = rc.as_ptr();
-        let alloc = unsafe { ptr::read(&rc.alloc) };
+    pub fn into_raw_with_allocator(self) -> (*const T, A) {
+        let this = mem::ManuallyDrop::new(self);
+        let result = this.as_ptr();
+        // Safety: `this` is ManuallyDrop so the allocator will not be double-dropped
+        let alloc = unsafe { ptr::read(&this.alloc) };
         (result, alloc)
     }
 
diff --git a/library/alloc/src/sync.rs b/library/alloc/src/sync.rs
index a925b544bc2..09739698a65 100644
--- a/library/alloc/src/sync.rs
+++ b/library/alloc/src/sync.rs
@@ -1496,6 +1496,34 @@ impl<T: ?Sized, A: Allocator> Arc<T, A> {
         ptr
     }
 
+    /// Consumes the `Arc`, returning the wrapped pointer and allocator.
+    ///
+    /// To avoid a memory leak the pointer must be converted back to an `Arc` using
+    /// [`Arc::from_raw_in`].
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(allocator_api)]
+    /// use std::sync::Arc;
+    /// use std::alloc::System;
+    ///
+    /// let x = Arc::new_in("hello".to_owned(), System);
+    /// let (ptr, alloc) = Arc::into_raw_with_allocator(x);
+    /// assert_eq!(unsafe { &*ptr }, "hello");
+    /// let x = unsafe { Arc::from_raw_in(ptr, alloc) };
+    /// assert_eq!(&*x, "hello");
+    /// ```
+    #[must_use = "losing the pointer will leak memory"]
+    #[unstable(feature = "allocator_api", issue = "32838")]
+    pub fn into_raw_with_allocator(this: Self) -> (*const T, A) {
+        let this = mem::ManuallyDrop::new(this);
+        let ptr = Self::as_ptr(&this);
+        // Safety: `this` is ManuallyDrop so the allocator will not be double-dropped
+        let alloc = unsafe { ptr::read(&this.alloc) };
+        (ptr, alloc)
+    }
+
     /// Provides a raw pointer to the data.
     ///
     /// The counts are not affected in any way and the `Arc` is not consumed. The pointer is valid for
@@ -2740,6 +2768,45 @@ impl<T: ?Sized, A: Allocator> Weak<T, A> {
         result
     }
 
+    /// Consumes the `Weak<T>`, returning the wrapped pointer and allocator.
+    ///
+    /// This converts the weak pointer into a raw pointer, while still preserving the ownership of
+    /// one weak reference (the weak count is not modified by this operation). It can be turned
+    /// back into the `Weak<T>` with [`from_raw_in`].
+    ///
+    /// The same restrictions of accessing the target of the pointer as with
+    /// [`as_ptr`] apply.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// #![feature(allocator_api)]
+    /// use std::sync::{Arc, Weak};
+    /// use std::alloc::System;
+    ///
+    /// let strong = Arc::new_in("hello".to_owned(), System);
+    /// let weak = Arc::downgrade(&strong);
+    /// let (raw, alloc) = weak.into_raw_with_allocator();
+    ///
+    /// assert_eq!(1, Arc::weak_count(&strong));
+    /// assert_eq!("hello", unsafe { &*raw });
+    ///
+    /// drop(unsafe { Weak::from_raw_in(raw, alloc) });
+    /// assert_eq!(0, Arc::weak_count(&strong));
+    /// ```
+    ///
+    /// [`from_raw_in`]: Weak::from_raw_in
+    /// [`as_ptr`]: Weak::as_ptr
+    #[must_use = "losing the pointer will leak memory"]
+    #[unstable(feature = "allocator_api", issue = "32838")]
+    pub fn into_raw_with_allocator(self) -> (*const T, A) {
+        let this = mem::ManuallyDrop::new(self);
+        let result = this.as_ptr();
+        // Safety: `this` is ManuallyDrop so the allocator will not be double-dropped
+        let alloc = unsafe { ptr::read(&this.alloc) };
+        (result, alloc)
+    }
+
     /// Converts a raw pointer previously created by [`into_raw`] back into `Weak<T>` in the provided
     /// allocator.
     ///
diff --git a/tests/ui/coroutine/static-move-suggestion.fixed b/tests/ui/coroutine/static-move-suggestion.fixed
new file mode 100644
index 00000000000..56445be4715
--- /dev/null
+++ b/tests/ui/coroutine/static-move-suggestion.fixed
@@ -0,0 +1,19 @@
+//@ run-rustfix
+
+// check to make sure that we suggest adding `move` after `static`
+
+#![feature(coroutines)]
+
+fn check() -> impl Sized {
+    let x = 0;
+    #[coroutine]
+    static move || {
+        //~^ ERROR E0373
+        yield;
+        x
+    }
+}
+
+fn main() {
+    check();
+}
diff --git a/tests/ui/coroutine/static-move-suggestion.rs b/tests/ui/coroutine/static-move-suggestion.rs
new file mode 100644
index 00000000000..1d6e4a62883
--- /dev/null
+++ b/tests/ui/coroutine/static-move-suggestion.rs
@@ -0,0 +1,19 @@
+//@ run-rustfix
+
+// check to make sure that we suggest adding `move` after `static`
+
+#![feature(coroutines)]
+
+fn check() -> impl Sized {
+    let x = 0;
+    #[coroutine]
+    static || {
+        //~^ ERROR E0373
+        yield;
+        x
+    }
+}
+
+fn main() {
+    check();
+}
diff --git a/tests/ui/coroutine/static-move-suggestion.stderr b/tests/ui/coroutine/static-move-suggestion.stderr
new file mode 100644
index 00000000000..6d890468b32
--- /dev/null
+++ b/tests/ui/coroutine/static-move-suggestion.stderr
@@ -0,0 +1,26 @@
+error[E0373]: coroutine may outlive the current function, but it borrows `x`, which is owned by the current function
+  --> $DIR/static-move-suggestion.rs:10:5
+   |
+LL |     static || {
+   |     ^^^^^^^^^ may outlive borrowed value `x`
+...
+LL |         x
+   |         - `x` is borrowed here
+   |
+note: coroutine is returned here
+  --> $DIR/static-move-suggestion.rs:10:5
+   |
+LL | /     static || {
+LL | |
+LL | |         yield;
+LL | |         x
+LL | |     }
+   | |_____^
+help: to force the coroutine to take ownership of `x` (and any other referenced variables), use the `move` keyword
+   |
+LL |     static move || {
+   |            ++++
+
+error: aborting due to 1 previous error
+
+For more information about this error, try `rustc --explain E0373`.
diff --git a/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.rs b/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.rs
index 0ae498c134f..d65bfee843e 100644
--- a/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.rs
+++ b/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.rs
@@ -7,6 +7,7 @@ fn _zero() {
     if false {
         unsafe { mem::zeroed() }
         //~^ warn: never type fallback affects this call to an `unsafe` function
+        //~| warn: this will change its meaning in a future release!
     } else {
         return;
     };
@@ -21,6 +22,7 @@ fn _trans() {
             struct Zst;
             core::mem::transmute(Zst)
             //~^ warn: never type fallback affects this call to an `unsafe` function
+            //~| warn: this will change its meaning in a future release!
         }
     } else {
         return;
@@ -36,6 +38,7 @@ fn _union() {
 
         unsafe { Union { a: () }.b }
         //~^ warn: never type fallback affects this union access
+        //~| warn: this will change its meaning in a future release!
     } else {
         return;
     };
@@ -45,6 +48,7 @@ fn _deref() {
     if false {
         unsafe { *ptr::from_ref(&()).cast() }
         //~^ warn: never type fallback affects this raw pointer dereference
+        //~| warn: this will change its meaning in a future release!
     } else {
         return;
     };
@@ -62,6 +66,7 @@ fn _only_generics() {
 
         unsafe { internally_create(x) }
         //~^ warn: never type fallback affects this call to an `unsafe` function
+        //~| warn: this will change its meaning in a future release!
 
         x.unwrap()
     } else {
@@ -73,9 +78,11 @@ fn _stored_function() {
     if false {
         let zeroed = mem::zeroed;
         //~^ warn: never type fallback affects this `unsafe` function
+        //~| warn: this will change its meaning in a future release!
 
         unsafe { zeroed() }
         //~^ warn: never type fallback affects this call to an `unsafe` function
+        //~| warn: this will change its meaning in a future release!
     } else {
         return;
     };
@@ -90,6 +97,7 @@ fn _only_generics_stored_function() {
         let x = None;
         let f = internally_create;
         //~^ warn: never type fallback affects this `unsafe` function
+        //~| warn: this will change its meaning in a future release!
 
         unsafe { f(x) }
 
@@ -113,6 +121,7 @@ fn _method() {
         unsafe {
             S(marker::PhantomData).create_out_of_thin_air()
             //~^ warn: never type fallback affects this call to an `unsafe` method
+            //~| warn: this will change its meaning in a future release!
         }
     } else {
         return;
@@ -129,6 +138,7 @@ fn _objc() {
         () => {
             match send_message::<_ /* ?0 */>() {
                 //~^ warn: never type fallback affects this call to an `unsafe` function
+                //~| warn: this will change its meaning in a future release!
                 Ok(x) => x,
                 Err(_) => loop {},
             }
diff --git a/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.stderr b/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.stderr
index 84c9385fd13..fbd92f8f662 100644
--- a/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.stderr
+++ b/tests/ui/never_type/lint-never-type-fallback-flowing-into-unsafe.stderr
@@ -4,75 +4,93 @@ warning: never type fallback affects this call to an `unsafe` function
 LL |         unsafe { mem::zeroed() }
    |                  ^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
    = note: `#[warn(never_type_fallback_flowing_into_unsafe)]` on by default
 
 warning: never type fallback affects this call to an `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:22:13
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:23:13
    |
 LL |             core::mem::transmute(Zst)
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this union access
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:37:18
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:39:18
    |
 LL |         unsafe { Union { a: () }.b }
    |                  ^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this raw pointer dereference
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:46:18
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:49:18
    |
 LL |         unsafe { *ptr::from_ref(&()).cast() }
    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this call to an `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:63:18
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:67:18
    |
 LL |         unsafe { internally_create(x) }
    |                  ^^^^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this call to an `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:77:18
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:83:18
    |
 LL |         unsafe { zeroed() }
    |                  ^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:74:22
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:79:22
    |
 LL |         let zeroed = mem::zeroed;
    |                      ^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:91:17
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:98:17
    |
 LL |         let f = internally_create;
    |                 ^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this call to an `unsafe` method
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:114:13
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:122:13
    |
 LL |             S(marker::PhantomData).create_out_of_thin_air()
    |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
 
 warning: never type fallback affects this call to an `unsafe` function
-  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:130:19
+  --> $DIR/lint-never-type-fallback-flowing-into-unsafe.rs:139:19
    |
 LL |             match send_message::<_ /* ?0 */>() {
    |                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
@@ -80,6 +98,8 @@ LL |             match send_message::<_ /* ?0 */>() {
 LL |         msg_send!();
    |         ----------- in this macro invocation
    |
+   = warning: this will change its meaning in a future release!
+   = note: for more information, see issue #123748 <https://github.com/rust-lang/rust/issues/123748>
    = help: specify the type explicitly
    = note: this warning originates in the macro `msg_send` (in Nightly builds, run with -Z macro-backtrace for more info)
 
diff --git a/tests/ui/rustc-env/README.md b/tests/ui/rustc-env/README.md
new file mode 100644
index 00000000000..ff674f3e6cc
--- /dev/null
+++ b/tests/ui/rustc-env/README.md
@@ -0,0 +1,6 @@
+Some environment variables affect rustc's behavior not because they are major compiler interfaces
+but rather because rustc is, ultimately, a Rust program, with debug logging, stack control, etc.
+
+Prefer to group tests that use environment variables to control something about rustc's core UX,
+like "can we parse this number of parens if we raise RUST_MIN_STACK?" with related code for that
+compiler feature.
diff --git a/tests/ui/auxiliary/rustc-rust-log-aux.rs b/tests/ui/rustc-env/auxiliary/rust-log-aux.rs
index 8080428d563..8080428d563 100644
--- a/tests/ui/auxiliary/rustc-rust-log-aux.rs
+++ b/tests/ui/rustc-env/auxiliary/rust-log-aux.rs
diff --git a/tests/ui/rustc-env/min-stack-banana.rs b/tests/ui/rustc-env/min-stack-banana.rs
new file mode 100644
index 00000000000..abbb6843710
--- /dev/null
+++ b/tests/ui/rustc-env/min-stack-banana.rs
@@ -0,0 +1,2 @@
+//@ rustc-env:RUST_MIN_STACK=banana
+fn main() {}
diff --git a/tests/ui/rustc-env/min-stack-banana.stderr b/tests/ui/rustc-env/min-stack-banana.stderr
new file mode 100644
index 00000000000..d379367ab4f
--- /dev/null
+++ b/tests/ui/rustc-env/min-stack-banana.stderr
@@ -0,0 +1,4 @@
+error: `RUST_MIN_STACK` should be a number of bytes, but was "banana"
+  |
+  = note: you can also unset `RUST_MIN_STACK` to use the default stack size
+
diff --git a/tests/ui/rustc-rust-log.rs b/tests/ui/rustc-env/rust-log.rs
index 299b6c40a56..10040754593 100644
--- a/tests/ui/rustc-rust-log.rs
+++ b/tests/ui/rustc-env/rust-log.rs
@@ -5,7 +5,7 @@
 //@ dont-check-compiler-stdout
 //@ dont-check-compiler-stderr
 //@ compile-flags: --error-format human
-//@ aux-build: rustc-rust-log-aux.rs
+//@ aux-build: rust-log-aux.rs
 //@ rustc-env:RUSTC_LOG=debug
 
 fn main() {}