Update Android testing to API 21, matching NDK 26

We were running testing on API 18, which was already out of support for
NDK 25, and some of the ancient behavior in that image was causing
trouble when developing `rustc` features (#120326).

Update to the current LTS NDK 26, and to its minimum supported API 21.

Fixes: #120567

2 files changed, 8 insertions, 5 deletions

diff --git a/src/bootstrap/src/utils/cc_detect.rs b/src/bootstrap/src/utils/cc_detect.rs
index 20d79e490ec..e947e3735db 100644
--- a/src/bootstrap/src/utils/cc_detect.rs
+++ b/src/bootstrap/src/utils/cc_detect.rs
@@ -247,10 +247,8 @@ pub(crate) fn ndk_compiler(compiler: Language, triple: &str, ndk: &Path) -> Path
         triple.to_string()
     };
 
-    // API 19 is the earliest API level supported by NDK r25b but AArch64 and x86_64 support
-    // begins at API level 21.
-    let api_level =
-        if triple.contains("aarch64") || triple.contains("x86_64") { "21" } else { "19" };
+    // The earliest API supported by NDK r26d is 21.
+    let api_level = "21";
     let compiler = format!("{}{}-{}", triple_translated, api_level, compiler.clang());
     let host_tag = if cfg!(target_os = "macos") {
         // The NDK uses universal binaries, so this is correct even on ARM.
@@ -258,7 +256,7 @@ pub(crate) fn ndk_compiler(compiler: Language, triple: &str, ndk: &Path) -> Path
     } else if cfg!(target_os = "windows") {
         "windows-x86_64"
     } else {
-        // NDK r25b only has official releases for macOS, Windows and Linux.
+        // NDK r26d only has official releases for macOS, Windows and Linux.
         // Try the Linux directory everywhere else, on the assumption that the OS has an
         // emulation layer that can cope (e.g. BSDs).
         "linux-x86_64"
diff --git a/src/bootstrap/src/utils/change_tracker.rs b/src/bootstrap/src/utils/change_tracker.rs
index 083418ed066..879cc079c6b 100644
--- a/src/bootstrap/src/utils/change_tracker.rs
+++ b/src/bootstrap/src/utils/change_tracker.rs
@@ -210,4 +210,9 @@ pub const CONFIG_CHANGE_HISTORY: &[ChangeInfo] = &[
         severity: ChangeSeverity::Info,
         summary: "the `wasm-component-ld` tool is now built as part of `build.extended` and can be a member of `build.tools`",
     },
+    ChangeInfo {
+        change_id: 120593,
+        severity: ChangeSeverity::Info,
+        summary: "Removed android-ndk r25b support in favor of android-ndk r26d.",
+    },
 ];