A try with MinGW-w64 also enabled

.github/workflows/ci-lazypg.yml

@@ -34,8 +34,8 @@ jobs:
 #           pg: 17
           - os: windows-latest
             cc: msvc
-#         - os: windows-latest
-#           cc: mingw
+          - os: windows-latest
+            cc: mingw
         java: [21]
 
     steps:
@@ -86,7 +86,8 @@ jobs:
           echo >>"$GITHUB_ENV" "ABS_JSHELL=$JAVA_HOME/bin/jshell"
         fi
 
-    - name: Set PGCONFIG in environment, installing PostgreSQL if needed
+    - name: Set PGCONFIG in environment, getting PostgreSQL if needed (!mingw)
+      if: ${{ 'mingw' != matrix.oscc.cc }}
       shell: bash
       env:
         PGVER: ${{ matrix.oscc.pg }}
@@ -111,6 +112,13 @@ jobs:
           echo >>"$GITHUB_ENV" PGCONFIG="$pfx/bin/pg_config"
         fi
 
+    - name: Set PGCONFIG in environment, getting PostgreSQL (mingw)
+      if: ${{ 'mingw' == matrix.oscc.cc }}
+      shell: C:\shells\msys2bash.cmd {0}
+      run: |
+        pacman -S --noconfirm mingw-w64-x86_64-postgresql
+        echo >>"$GITHUB_ENV" PGCONFIG='c:\msys64\mingw64\bin\pg_config'
+
     - name: Report Java, Maven, and PostgreSQL versions
       shell: bash
       run: |
@@ -181,7 +189,7 @@ jobs:
       # with Actions bash prepending stuff to the just-carefully-created PATH
       shell: cmd
       run: |
-        %M2%\mvn clean install --batch-mode ^
+        mvn clean install --batch-mode ^
           -Dpgsql.pgconfig="%PGCONFIG%" ^
           -Psaxon-examples -Ppgjdbc ^
           -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn
@@ -198,46 +206,8 @@ jobs:
     - name: Build PL/Java (Windows MinGW-w64)
       if: ${{ 'Windows' == runner.os && 'mingw' == matrix.oscc.cc }}
       working-directory: pljava
-      #
-      # GitHub Actions will allow 'bash' as a shell choice, even on a Windows
-      # runner, in which case it's the bash from Git for Windows. That isn't the
-      # same as the msys64\usr\bin\bash that we want; what's more, while both
-      # rely on a cygwin DLL, they don't rely on the same one, and an attempt
-      # to exec one from the other leads to a "fatal error - cygheap base
-      # mismatch". So, the bash we want has to be started by something other
-      # than the bash we've got. In this case, set shell: to a command that
-      # will use cmd to start the right bash.
-      #
-      # Some of the MinGW magic is set up by the bash profile run at "login", so
-      # bash must be started with -l. That profile ends with a cd $HOME, so to
-      # avoid changing the current directory, set HOME=. first (credit for that:
-      # https://superuser.com/a/806371). As set above, . is really the pljava
-      # working-directory, so the bash script should start by resetting HOME to
-      # the path of its parent.
-      #
-      # The runner is provisioned with a very long PATH that includes separate
-      # bin directories for pre-provisioned packages. The MinGW profile replaces
-      # that with a much shorter path, so mvn and pg_config below must be given
-      # as absolute paths (using M2 and PGBIN supplied in the environment) or
-      # they won't be found. As long as mvn itself can be found, it is able
-      # to find java without difficulty, using the JAVA_HOME that is also in
-      # the environment.
-      #
-      # Those existing variables in the environment are all spelled in Windows
-      # style with drive letters, colons, and backslashes, rather than the MinGW
-      # unixy style, but the mingw bash doesn't seem to object.
-      #
-      # If you use the runner-supplied bash to examine the environment, you will
-      # see MSYSTEM=MINGW64 already in it, but that apparently is something the
-      # runner-supplied bash does. It must be set here before invoking the MinGW
-      # bash directly.
-      #
-      env:
-        HOME: .
-        MSYSTEM: MINGW64
-      shell: 'cmd /C "c:\msys64\usr\bin\bash -l "{0}""'
+      shell: C:\shells\msys2bash.cmd {0}
       run: |
-        HOME=$( (cd .. && pwd) )
         "$M2"/mvn clean install --batch-mode \
           -Dpgsql.pgconfig="$PGCONFIG" \
           -Psaxon-examples -Ppgjdbc \