Deb: Remove build depencency libreadline-gplv2-dev no longer available

The Readline library is no longer available in Debian Sid.
See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=980504

Add the dependency on-the-fly in autobake-deb.sh for older distro versions
and keep the native build in a state that works on Debian Sid as-is.

debian/autobake-deb.sh

@@ -18,10 +18,20 @@ set -e
 export DEB_BUILD_OPTIONS="nocheck $DEB_BUILD_OPTIONS"
 
 # Take the files and part of control from MCS directory
-if [[ -d storage/columnstore/columnstore/debian ]]; then
+if [[ -d storage/columnstore/columnstore/debian ]]
+then
   cp -v storage/columnstore/columnstore/debian/mariadb-plugin-columnstore.* debian/
   echo >> debian/control
   cat storage/columnstore/columnstore/debian/control >> debian/control
+
+  # From Debian Bullseye/Ubuntu Hirsute onwards libreadline is gone, so build with it
+  # only on older releases where it is still available. This can be removed once
+  # MCOL-4535 lands in MariaDB.
+  if apt-cache madison libreadline-gplv2-dev | grep 'libreadline-gplv2-dev' >/dev/null 2>&1
+  then
+    sed 's/libpcre2-dev,/libpcre2-dev, libreadline-gplv2-dev [amd64],/' -i debian/control
+  fi
+
   # ColumnStore is explcitly disabled in the native build, so allow it now
   # when build it when triggered by autobake-deb.sh
   sed '/-DPLUGIN_COLUMNSTORE=NO/d' -i debian/rules
@@ -75,7 +85,7 @@ then
   echo "usr/bin/sst_dump" >> debian/mariadb-plugin-rocksdb.install
 fi
 
-# From Debian Buster/Ubuntu Bionic, libcurl4 replaces libcurl3.
+# From Debian Buster/Ubuntu Bionic, libcurl4 replaces libcurl3
 if ! apt-cache madison libcurl4 | grep 'libcurl4' >/dev/null 2>&1
 then
   sed 's/libcurl4/libcurl3/g' -i debian/control

debian/control

@@ -35,7 +35,6 @@ Build-Depends: bison,
                libnuma-dev [linux-any],
                libpam0g-dev,
                libpcre2-dev,
-               libreadline-gplv2-dev [amd64],
                libsnappy-dev,
                libssl-dev,
                libssl-dev:native,

debian/salsa-ci.yml

@@ -37,6 +37,14 @@ build:
     - apt-get update && eatmydata apt-get install --yes --no-install-recommends aptitude devscripts ccache equivs
     - cd ${WORKING_DIR}/${SOURCE_DIR}
     - eatmydata install-build-deps.sh .
+    - |
+      # From Debian Bullseye/Ubuntu Hirsute onwards libreadline is gone, so build with it
+      # only on older releases where it is still available. This can be removed once
+      # MCOL-4535 lands in MariaDB.
+      if apt-cache madison libreadline-gplv2-dev | grep 'libreadline-gplv2-dev' >/dev/null 2>&1
+      then
+       apt-get install --yes libreadline-gplv2-dev
+      fi
     - update-ccache-symlinks; ccache -z # Zero out ccache counters
     - while true; do sleep 600; echo "10 minutes passed" >&2; done & # Progress keeper since build is long and silent
     - debian/autobake-deb.sh |& tail -n 10000 # Keep Gitlab-CI output under 4 MB