diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 04a0017a3504..308bc55ead71 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -101,7 +101,8 @@ jobs:
         ./y.sh prepare --only-libcore
         # TODO: remove --features master when it is back to the default.
         ./y.sh build --features master
-        cargo test
+        # TODO: remove --features master when it is back to the default.
+        cargo test --features master
         ./clean_all.sh
 
     - name: Prepare dependencies
diff --git a/.github/workflows/failures.yml b/.github/workflows/failures.yml
index 7fcc0bfe75f2..ae8de79b773d 100644
--- a/.github/workflows/failures.yml
+++ b/.github/workflows/failures.yml
@@ -21,11 +21,14 @@ jobs:
         libgccjit_version:
           - gcc: "libgccjit.so"
             artifacts_branch: "master"
+            # TODO: switch back to --no-default-features in the case of libgccjit 12 when the default is to enable
+            # master again.
+            extra: "--features master"
           - gcc: "libgccjit_without_int128.so"
             artifacts_branch: "master-without-128bit-integers"
+            extra: "--features master"
           - gcc: "libgccjit12.so"
             artifacts_branch: "gcc12"
-            extra: "--no-default-features"
             # FIXME(antoyo): we need to set GCC_EXEC_PREFIX so that the linker can find the linker plugin.
             # Not sure why it's not found otherwise.
             env_extra: "TEST_FLAGS='-Cpanic=abort -Zpanic-abort-tests' GCC_EXEC_PREFIX=/usr/lib/gcc/"
@@ -125,6 +128,5 @@ jobs:
     - name: Run tests
       id: tests
       run: |
-        # TODO: remove --features master when it is back to the default.
-        ${{ matrix.libgccjit_version.env_extra }} ./test.sh --release --features master --clean --build-sysroot --test-failing-rustc ${{ matrix.libgccjit_version.extra }} | tee output_log
+        ${{ matrix.libgccjit_version.env_extra }} ./test.sh --release --clean --build-sysroot --test-failing-rustc ${{ matrix.libgccjit_version.extra }} | tee output_log
         rg --text "test result" output_log >> $GITHUB_STEP_SUMMARY
diff --git a/.github/workflows/m68k.yml b/.github/workflows/m68k.yml
index 51e8c084061c..4d9d7e23dc2b 100644
--- a/.github/workflows/m68k.yml
+++ b/.github/workflows/m68k.yml
@@ -116,7 +116,8 @@ jobs:
         ./y.sh prepare --only-libcore --cross
         # TODO: remove --features master when it is back to the default.
         ./y.sh build --target-triple m68k-unknown-linux-gnu --features master
-        CG_GCC_TEST_TARGET=m68k-unknown-linux-gnu cargo test
+        # TODO: remove --features master when it is back to the default.
+        CG_GCC_TEST_TARGET=m68k-unknown-linux-gnu cargo test --features master
         ./clean_all.sh
 
     - name: Prepare dependencies
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index de37123f951d..43b90fcec933 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -80,7 +80,8 @@ jobs:
         ./y.sh prepare --only-libcore
         # TODO: remove --features master when it is back to the default.
         EMBED_LTO_BITCODE=1 ./y.sh build --release --release-sysroot --features master
-        cargo test
+        # TODO: remove --features master when it is back to the default.
+        cargo test --features master
         ./clean_all.sh
 
     - name: Prepare dependencies
diff --git a/.github/workflows/stdarch.yml b/.github/workflows/stdarch.yml
index af6f399b52a9..42109ba3e024 100644
--- a/.github/workflows/stdarch.yml
+++ b/.github/workflows/stdarch.yml
@@ -92,9 +92,10 @@ jobs:
     - name: Build
       run: |
         ./y.sh prepare --only-libcore
-        # TODO: remove --features master when it is back to the default.
+        # TODO: remove `--features master` when it is back to the default.
         ./y.sh build --release --release-sysroot --features master
-        cargo test
+        # TODO: remove --features master when it is back to the default.
+        cargo test --features master
 
     - name: Clean
       if: ${{ !matrix.cargo_runner }}
@@ -112,12 +113,14 @@ jobs:
       uses: actions-rs/cargo@v1.0.3
       with:
         command: build
-        args: --release
+        # TODO: remove `--features master` when it is back to the default.
+        args: --release --features master
 
     - name: Run tests
       if: ${{ !matrix.cargo_runner }}
       run: |
-        ./test.sh --release --clean --release-sysroot --build-sysroot --mini-tests --std-tests --test-libcore
+        # TODO: remove `--features master` when it is back to the default.
+        ./test.sh --release --clean --release-sysroot --build-sysroot --mini-tests --std-tests --test-libcore --features master
 
     - name: Run stdarch tests
       if: ${{ !matrix.cargo_runner }}
diff --git a/failing-ui-tests12.txt b/failing-ui-tests12.txt
index 24ef7bb8d709..4af93939b064 100644
--- a/failing-ui-tests12.txt
+++ b/failing-ui-tests12.txt
@@ -39,3 +39,4 @@ tests/ui/sse2.rs
 tests/ui/codegen/issue-79865-llvm-miscompile.rs
 tests/ui/intrinsics/intrinsics-integer.rs
 tests/ui/std-backtrace.rs
+tests/ui/mir/alignment/packed.rs