Explicitly model missing upstream

It shouldn't really happen, but if it does, at least we will have an explicit record of it.

3 files changed, 13 insertions, 1 deletions

diff --git a/src/bootstrap/src/core/build_steps/gcc.rs b/src/bootstrap/src/core/build_steps/gcc.rs
index 867874fc7cc..94abbb35ac5 100644
--- a/src/bootstrap/src/core/build_steps/gcc.rs
+++ b/src/bootstrap/src/core/build_steps/gcc.rs
@@ -129,6 +129,10 @@ fn try_download_gcc(builder: &Builder<'_>, target: TargetSelection) -> Option<Pa
             eprintln!("Found local GCC modifications, GCC will *not* be downloaded");
             None
         }
+        PathFreshness::MissingUpstream => {
+            eprintln!("No upstream commit found, GCC will *not* be downloaded");
+            None
+        }
     }
 }
 
diff --git a/src/bootstrap/src/core/config/config.rs b/src/bootstrap/src/core/config/config.rs
index 1406ebeb621..a2d13cffbff 100644
--- a/src/bootstrap/src/core/config/config.rs
+++ b/src/bootstrap/src/core/config/config.rs
@@ -3210,6 +3210,10 @@ impl Config {
 
                     upstream
                 }
+                PathFreshness::MissingUpstream => {
+                    eprintln!("No upstream commit found");
+                    return None;
+                }
             }
         } else {
             channel::read_commit_info_file(&self.src)
@@ -3289,7 +3293,7 @@ impl Config {
     pub fn has_changes_from_upstream(&self, paths: &[&str]) -> bool {
         match self.check_modifications(paths) {
             PathFreshness::LastModifiedUpstream { .. } => false,
-            PathFreshness::HasLocalModifications { .. } => true,
+            PathFreshness::HasLocalModifications { .. } | PathFreshness::MissingUpstream => true,
         }
     }
 
diff --git a/src/bootstrap/src/core/download.rs b/src/bootstrap/src/core/download.rs
index 3c9cfead5a9..0051b874729 100644
--- a/src/bootstrap/src/core/download.rs
+++ b/src/bootstrap/src/core/download.rs
@@ -734,6 +734,10 @@ download-rustc = false
             match detect_llvm_freshness(self, self.rust_info.is_managed_git_subrepository()) {
                 PathFreshness::LastModifiedUpstream { upstream } => upstream,
                 PathFreshness::HasLocalModifications { upstream } => upstream,
+                PathFreshness::MissingUpstream => {
+                    eprintln!("No upstream commit for downloading LLVM found");
+                    crate::exit!(1);
+                }
             };
         let stamp_key = format!("{}{}", llvm_sha, self.llvm_assertions);
         let llvm_stamp = BuildStamp::new(&llvm_root).with_prefix("llvm").add_stamp(stamp_key);