export cflags to try to find augeas.h

.github/actions/run_tox/action.yml

@@ -1,4 +1,4 @@
-name: run_tox
+name: Run tox
 
 inputs:
   AWS_ACCESS_KEY_ID:

.github/actions/setup_tox/action.yml

@@ -1,4 +1,4 @@
-name: setup_tox
+name: Setup tox
 
 inputs:
   AWS_TEST_FARM_PEM:
@@ -12,6 +12,13 @@ inputs:
 runs:
   using: composite
   steps:
+  # We run brew update because we've seen attempts to install an older version
+  # of a package fail. See
+  # https://github.com/actions/virtual-environments/issues/3165.
+  #
+  # We untap homebrew/core and homebrew/cask and unset HOMEBREW_NO_INSTALL_FROM_API (which
+  # is maybe set by the CI macOS env) because GitHub has been having issues, making these jobs
+  # fail on git clones: https://github.com/orgs/Homebrew/discussions/4612.
   - name: Install MacOS dependencies
     if: runner.os == 'macOS'
     run: |-
@@ -20,6 +27,8 @@ runs:
       brew untap homebrew/core homebrew/cask
       brew update
       brew install augeas
+      BREW_PREFIX=$(brew --prefix)
+      export CFLAGS="$CFLAGS -I$BREW_PREFIX/include -L$BREW_PREFIX/lib"
     shell: bash
   - name: Install Linux dependencies
     if: runner.os == 'Linux'