gnu-tests: create full partition for tac-continue

tac/tac-continue test needs a temporary directory which is on a
partition in which you can still create files, but where no free space
is left.

Author: martinkunkel2

.github/workflows/GnuTests.yml

@@ -1,12 +1,11 @@
 name: GnuTests
 
-# spell-checker:ignore (abbrev/names) CodeCov gnulib GnuTests Swatinem
+# spell-checker:ignore (abbrev/names) CodeCov gnulib GnuTests Swatinem tmpfs
 # spell-checker:ignore (jargon) submodules devel
 # spell-checker:ignore (libs/utils) autopoint chksum getenforce gperf lcov libexpect limactl pyinotify setenforce shopt texinfo valgrind libattr libcap taiki-e
 # spell-checker:ignore (options) Ccodegen Coverflow Cpanic Zpanic
 # spell-checker:ignore (people) Dawid Dziurla * dawidd dtolnay
 # spell-checker:ignore (vars) FILESET SUBDIRS XPASS
-
 # * note: to run a single test => `REPO/util/run-gnu-test.sh PATH/TO/TEST/SCRIPT`
 
 on:
@@ -115,6 +114,16 @@ jobs:
         cd 'uutils'
         env PROFILE=release-small bash util/build-gnu.sh
 
+    ### Test environment setup
+    - name: Setup specific GNU tests environment
+      shell: bash
+      run: |
+        # for tac/tac-continue test
+        export FULL_PARTITION_TMPDIR=/mnt/full_partition
+        sudo mount --mkdir=0777 --types tmpfs --options size=1M tmpfs $FULL_PARTITION_TMPDIR
+        dd if=/dev/zero of=$FULL_PARTITION_TMPDIR/data bs=1M count=1
+        echo "FULL_PARTITION_TMPDIR=$FULL_PARTITION_TMPDIR" >> $GITHUB_ENV
+
     ### Run tests as user
     - name: Run GNU tests
       shell: bash

util/why-skip.md

@@ -35,9 +35,6 @@
 = timeout returned 142. SIGALRM not handled? =
 * tests/misc/timeout-group.sh
 
-= FULL_PARTITION_TMPDIR not defined =
-* tests/misc/tac-continue.sh
-
 = can't get window size =
 * tests/misc/stty-row-col.sh