Try adding an additional rust-cache directory.

.github/workflows/build-all.yml

@@ -72,9 +72,14 @@ jobs:
 
     # Set up Rust, this is mainly used for rust-cache.
     # This action installs the 'minimal' profile.
+    # Even on Linux ARM this is necessary because rust-cache uses it.
     - uses: dtolnay/rust-toolchain@stable
 
     - uses: Swatinem/rust-cache@v2
+      with:
+        # This additional directory is because the home directory inside containers
+        # is different than the one outside of it.
+        cache-directories: ${{ runner.temp }}/_github_home/.cargo
 
     - name: Debugging information
       run: |

.github/workflows/scripts/build.sh

@@ -27,8 +27,8 @@ git config --global --add safe.directory "$GITHUB_WORKSPACE"
 # During the tag build, cabal/GHC may not realize that they have to rebuild the Version.hs file because the tag is invisible to it.
 # This line adds a comment to our version source file to prompt cabal/GHC to rebuild Version.hs.
 echo "{- $GITHUB_RUN_ID -}" >> src/App/Version.hs
-cabal update --verbose
-cabal build --verbose --project-file="$PROJECT_FILE" all
+cabal update
+cabal build --project-file="$PROJECT_FILE" all
 cabal test --project-file="$PROJECT_FILE" unit-tests
 
 # TODO: Bring this back.