Make CI behavior for diffs more consistent

While some of our determinism checks fail for trivial cases
(specifically for macOS and Windows builds), we still want CI jobs
to fail to ensure they get manual verification.

Author: TheBlueMatt

.github/workflows/build.yml

@@ -250,6 +250,15 @@ jobs:
         with:
           name: org.ldk.nupkg
           path: c_sharp/org.ldk.nupkg
+      - name: Run test against C# release library
+        shell: bash
+        run: |
+          cd c_sharp
+          sed 's/net.\.0/net9.0/' -i tests.csproj
+          ln -s ./packaging_artifacts/runtimes/linux-x64/native/libldkcsharp.so ./
+          LD_LIBRARY_PATH=. dotnet run --project tests.csproj
+          LD_LIBRARY_PATH=. dotnet run --project tests.csproj --configuration Release
+          git checkout tests.csproj
       - name: Check latest auto-generated code is in git
         run: |
           # Checkout files that get updated with version information
@@ -275,16 +284,9 @@ jobs:
           export LDK_GARBAGECOLLECTED_GIT_OVERRIDE="$(git describe --tag HEAD)"
           if ! diff ldk-java-bins/"${LDK_GARBAGECOLLECTED_GIT_OVERRIDE}/"org.ldk.nupkg c_sharp/org.ldk.nupkg; then
             dnf -y install diffoscope mono-devel
-            diffoscope ldk-java-bins/"${LDK_GARBAGECOLLECTED_GIT_OVERRIDE}/"org.ldk.nupkg c_sharp/org.ldk.nupkg || echo
+            diffoscope --max-diff-input-lines 0 ldk-java-bins/"${LDK_GARBAGECOLLECTED_GIT_OVERRIDE}/"org.ldk.nupkg c_sharp/org.ldk.nupkg || echo
             exit 1
           fi
-      - name: Run test against C# release library
-        shell: bash
-        run: |
-          cd c_sharp
-          ln -s ./packaging_artifacts/runtimes/linux-x64/native/libldkcsharp.so ./
-          LD_LIBRARY_PATH=. dotnet run --project tests.csproj
-          LD_LIBRARY_PATH=. dotnet run --project tests.csproj --configuration Release
 
   osx_c_sharp:
     strategy:
@@ -628,15 +630,18 @@ jobs:
         shell: bash
         run: |
           export LDK_GARBAGECOLLECTED_GIT_OVERRIDE="$(git describe --tag HEAD)"
+          SOME_DIFF=0
           for F in liblightningjni_MacOSX-{x86_64,aarch64}{,-leaktracking}.nativelib; do
             if ! diff "ldk-java-bins/${LDK_GARBAGECOLLECTED_GIT_OVERRIDE}/$F" "src/main/resources/$F"; then
               apt-get -y install diffoscope
               # Sadly these binaries are still non-deterministic, but only due
               # to a few-byte tag, thus we use diffoscope to ensure there
-              # aren't any "real" differences and move on.
+              # aren't any "real" differences but still fail the job.
               diffoscope "ldk-java-bins/${LDK_GARBAGECOLLECTED_GIT_OVERRIDE}/$F" "src/main/resources/$F" || echo
+              SOME_DIFF=1
             fi
           done
+          exit $SOME_DIFF
 
   android:
     runs-on: ubuntu-latest