diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 444f20b35ef..f2fdaf5ac75 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -36,6 +36,13 @@ jobs:
       - name: Install nox
         run: python -m pip install --upgrade pip && pip install nox
 
+      - name: Check rust-src
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
+
+      - name: Check rustup components
+        run: rustup component list --installed
+
       - name: Install Rust toolchain
         uses: dtolnay/rust-toolchain@master
         with:
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 77349974669..bf58b0bdd9c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -17,6 +17,25 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
+  rustup-repro:
+    if: github.ref != 'refs/heads/main'
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check rust-src
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
+      - name: Check rustup components
+        run: rustup component list --installed
+      - name: Check rust-src (2)
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt
+      - name: Check rust-src (3)
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
+
   fmt:
     if: github.ref != 'refs/heads/main'
     runs-on: ubuntu-latest
@@ -24,11 +43,17 @@ jobs:
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v4
       - run: python -m pip install --upgrade pip && pip install nox
+      - name: Check rust-src
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
       - uses: dtolnay/rust-toolchain@stable
         with:
           components: rustfmt
       - name: Check python formatting and lints (ruff)
         run: nox -s ruff
+      - name: Check rust-src again
+        run: ls -l /home/runner/.rustup/toolchains/*/lib/rustlib/src/rust
+        continue-on-error: true
       - name: Check rust formatting (rustfmt)
         run: nox -s rustfmt