Fail the CI if an optional module fails to compile (pythonGH-27466)

.github/workflows/build.yml

@@ -119,6 +119,8 @@ jobs:
     runs-on: macos-latest
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
+    env:
+      PYTHONSTRICTEXTENSIONBUILD: 1
     steps:
     - uses: actions/checkout@v2
     - name: Configure CPython
@@ -137,6 +139,7 @@ jobs:
     if: needs.check_source.outputs.run_tests == 'true'
     env:
       OPENSSL_VER: 1.1.1k
+      PYTHONSTRICTEXTENSIONBUILD: 1
     steps:
     - uses: actions/checkout@v2
     - name: Register gcc problem matcher
@@ -227,6 +230,7 @@ jobs:
     if: needs.check_source.outputs.run_tests == 'true'
     env:
       OPENSSL_VER: 1.1.1k
+      PYTHONSTRICTEXTENSIONBUILD: 1
       ASAN_OPTIONS: detect_leaks=0:allocator_may_return_null=1:handle_segv=0
     steps:
     - uses: actions/checkout@v2

.travis.yml

@@ -18,6 +18,7 @@ env:
     # Set rpath with env var instead of -Wl,-rpath linker flag
     # OpenSSL ignores LDFLAGS when linking bin/openssl
     - LD_RUN_PATH="${OPENSSL_DIR}/lib"
+    - PYTHONSTRICTEXTENSIONBUILD=1
 
 branches:
   only:

setup.py

@@ -571,6 +571,9 @@ def print_three_column(lst):
                 print("Custom linker flags may require --with-openssl-rpath=auto")
             print()
 
+        if os.environ.get("PYTHONSTRICTEXTENSIONBUILD") and (self.failed or self.failed_on_import):
+            raise RuntimeError("Failed to build some stdlib modules")
+
     def build_extension(self, ext):
 
         if ext.name == '_ctypes':