From 6736c78639300ac50298b4003eea2c5dea90885c Mon Sep 17 00:00:00 2001
From: Charles Harris <charlesr.harris@gmail.com>
Date: Tue, 15 Nov 2022 13:03:44 -0700
Subject: [PATCH 1/2] CI: Update to Ubuntu 18.04 to 20.04

Github actions will drop support for 18.04 April 1, 2023. There
are now sporadic test cancelations due to warning brownouts, and
the NumPy 1.24.x release will overlap that date, so increase the Ubuntu
version.

The main change here is that there is no support for gcc-6 in Ubuntu
20.04, so testing with that version is also dropped.
---
 .github/workflows/build_test.yml | 20 ++++++++------------
 azure-pipelines.yml              |  2 +-
 2 files changed, 9 insertions(+), 13 deletions(-)

diff --git a/.github/workflows/build_test.yml b/.github/workflows/build_test.yml
index 53fa13f7671a..2a1f5fc08a73 100644
--- a/.github/workflows/build_test.yml
+++ b/.github/workflows/build_test.yml
@@ -80,8 +80,8 @@ jobs:
 
   old_gcc:
     needs: [smoke_test]
-    # provides GCC 6, 7, 8
-    runs-on: ubuntu-18.04
+    # provides GCC  7, 8
+    runs-on: ubuntu-20.04
     steps:
     - uses: actions/checkout@v3
       with:
@@ -99,14 +99,7 @@ jobs:
         pythonx -m pip install --upgrade pip setuptools wheel
         pythonx -m pip install -r test_requirements.txt
     - name: Install Compilers
-      run: sudo apt install g++-6 g++-7 g++-8 -y
-    - name: Build gcc-6
-      run: |
-        export CC=/usr/bin/gcc-6
-        export CXX=/usr/bin/g++-6
-        pythonx setup.py install --user
-    - name: Runtests gcc-6
-      run: pythonx runtests.py -n
+      run: sudo apt install g++-7 g++-8 -y
     - name: Build gcc-7
       run: |
         export CC=/usr/bin/gcc-7
@@ -199,11 +192,14 @@ jobs:
 
   full:
     needs: [smoke_test]
-    runs-on: ubuntu-18.04
+    runs-on: ubuntu-20.04
     env:
       USE_WHEEL: 1
       RUN_FULL_TESTS: 1
-      RUN_COVERAGE: 1
+      # The coverage option fails with internal compiler error
+      # in coverage.c with Ubunto 20.04. That problem is fixed
+      # in 22.04, but there are other, new errors.
+      #RUN_COVERAGE: 1
       INSTALL_PICKLE5: 1
     steps:
     - uses: actions/checkout@v3
diff --git a/azure-pipelines.yml b/azure-pipelines.yml
index 922b7c8b2b43..d393077b8416 100644
--- a/azure-pipelines.yml
+++ b/azure-pipelines.yml
@@ -74,7 +74,7 @@ stages:
   - job: Lint
     condition: and(succeeded(), eq(variables['Build.Reason'], 'PullRequest'))
     pool:
-      vmImage: 'ubuntu-18.04'
+      vmImage: 'ubuntu-20.04'
     steps:
     - task: UsePythonVersion@0
       inputs:

From c5e30a8b9789d115fcb0219aca19f47219a14847 Mon Sep 17 00:00:00 2001
From: Charles Harris <charlesr.harris@gmail.com>
Date: Wed, 16 Nov 2022 17:42:39 -0700
Subject: [PATCH 2/2] DOC: Add compatibility release note.

We have dropped GCC-6 build testing.
---
 doc/release/upcoming_changes/22598.compatibility.rst | 5 +++++
 1 file changed, 5 insertions(+)
 create mode 100644 doc/release/upcoming_changes/22598.compatibility.rst

diff --git a/doc/release/upcoming_changes/22598.compatibility.rst b/doc/release/upcoming_changes/22598.compatibility.rst
new file mode 100644
index 000000000000..9be468798972
--- /dev/null
+++ b/doc/release/upcoming_changes/22598.compatibility.rst
@@ -0,0 +1,5 @@
+NumPy builds are no longer tested on GCC-6
+------------------------------------------
+Ubuntu 18.04 is deprecated for GitHub actions and GCC-6 is not available on
+Ubuntu 20.04, so builds using that compiler are no longer tested. We still test
+builds using GCC-7 and GCC-8.