Some small fixes to the CI job

.github/workflows/dev.yml

@@ -232,6 +232,9 @@ jobs:
           maint/RunPerlTest
 
   chaffinch:
+    # Job to verify that the CMake "unity" build (single-file / jumbo build) passes.
+    # If this fails, it's usually because two different files define some file-static
+    # functions or macros which collide.
     name: CMake unity build
     runs-on: ubuntu-latest
     steps:
@@ -250,13 +253,18 @@ jobs:
         run: cd build && ctest -j3 --output-on-failure
 
   heron:
+    # Job to verify that the tasks performed by PrepareRelease have been done. It is
+    # the committer's responsibility (currently) to run PrepareRelease themselves when
+    # making a PR, so that everything is kept in-sync.
     name: Check for PrepareRelease cleanliness
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-24.04 # TODO: Update to ubuntu-latest when that switches to 24.04
     steps:
       - name: Checkout
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           submodules: false
+          fetch-depth: 0
+          fetch-tags: false
 
       - name: PrepareRelease
         run: maint/PrepareRelease

maint/PrepareRelease

@@ -97,8 +97,8 @@ echo "Making pcre2demo.3"
 perl <<"END" >pcre2demo.3
   use Time::Piece;
   open(VH, "<", "../src/config.h.generic") || die "Failed to open src/config.h.generic\n";
-  open(IN, "../src/pcre2demo.c") || die "Failed to open src/pcre2demo.c\n";
-  open(OUT, ">pcre2demo.3") || die "Failed to open pcre2demo.3\n";
+  open(IN, "<", "../src/pcre2demo.c") || die "Failed to open src/pcre2demo.c\n";
+  open(OUT, ">", "pcre2demo.3") || die "Failed to open pcre2demo.3\n";
   my $version;
   while (<VH>)
   {