Add /dev/disk/by-id/ symlink in CI for test_BlockSpecial

This previous commit [1] excluded unit test
BlockSpecialTest.NamedBlockSpecialObjectBySymlinkMatches because GNOME
GitLab Docker CI images don't have /dev/disk hierarchy and so no
symbolic links to block devices.

Create the /dev/disk/by-id directory and a symlink for this unit test to
use in the new tests/makedev.sh script.

[1] fe2fc33e67
    Exclude unit test which fails in Docker CI image (!4)

.gitlab-ci.yml

@@ -58,11 +58,9 @@ stages:
     - nproc=`grep -c '^processor' /proc/cpuinfo` || nproc=1
     - echo nproc=$nproc
     - make -j $nproc
-    # Exclude specific unit test which fails without /dev/disk in Docker images.
-    - export GTEST_FILTER='-BlockSpecialTest.NamedBlockSpecialObjectBySymlinkMatches'
     # Exclude specific unit tests which fail without being able to create
     # loop devices in Docker images.
-    - GTEST_FILTER+=':My/SupportedFileSystemsTest.Create/lvm2pv'
+    - export GTEST_FILTER='-My/SupportedFileSystemsTest.Create/lvm2pv'
     - GTEST_FILTER+=':My/SupportedFileSystemsTest.CreateAndReadUsage/btrfs'
     - GTEST_FILTER+=':My/SupportedFileSystemsTest.CreateAndReadUsage/lvm2pv'
     - GTEST_FILTER+=':My/SupportedFileSystemsTest.CreateAndReadUsage/nilfs2'

tests/makedev.sh

@@ -22,3 +22,12 @@ do
 		chown root:disk "$name"
 	fi
 done
+
+# Create /dev/disk/by-id/SYMLINK to first block special device named in
+# /proc/partitions, if directory doesn't already exist, for
+# test_BlockSpecial.
+if test ! -e /dev/disk/by-id; then
+	mkdir -v -m 0755 -p /dev/disk/by-id/
+	dev=`awk '$1=="major" {next} NF==4 {print $4; exit}' /proc/partitions`
+	ln -v -s "/dev/$dev" "/dev/disk/by-id/gparted-$dev"
+fi