Skip tests that rely on unlinkat(2) behavior that varies between
kernel versions and is unspecified.

See <http://bugs.gnu.org/20597>
and <http://lists.gnu.org/archive/html/bug-tar/2015-06/msg00000.html>.

--- tar-1.28/tests/testsuite	2014-07-27 22:35:27.000000000 +0200
+++ tar-1.28/tests/testsuite	2015-06-16 00:21:16.906380739 +0200
@@ -34680,6 +34680,7 @@ find .
 )"
 at_fn_check_prepare_notrace 'an embedded newline' "remfiles08a.at:31"
 ( $at_check_trace;
+exit 77
 mkdir gnu
 (cd gnu
 TEST_TAR_FORMAT=gnu
@@ -34762,6 +34763,7 @@ find .
 )"
 at_fn_check_prepare_notrace 'an embedded newline' "remfiles08b.at:36"
 ( $at_check_trace;
+exit 77
 mkdir gnu
 (cd gnu
 TEST_TAR_FORMAT=gnu
@@ -34850,6 +34852,7 @@ find .
 )"
 at_fn_check_prepare_notrace 'a `...` command substitution' "remfiles08c.at:31"
 ( $at_check_trace;
+exit 77
 mkdir gnu
 (cd gnu
 TEST_TAR_FORMAT=gnu
s='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
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<div class='path'>path: <a href='/guix/log/?id=1ec6796c5f2c2beb8c610b6a128839941234aa5b'>root</a>/<a href='/guix/log/m4?id=1ec6796c5f2c2beb8c610b6a128839941234aa5b'>m4</a></div><div class='content'><table class='list nowrap'><tr class='nohover'><th class='left'>Age</th><th class='left'>Commit message (<a href='/guix/log/m4?id=1ec6796c5f2c2beb8c610b6a128839941234aa5b&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-11-07 18:07:11 +0200'>2023-11-07</span></td><td><a href='/guix/commit/m4?id=220759226e93d76d8d80058f69f9d8b29714bbde'>build: Fix spelling in m4 macros.</a><span class='msg-avail'>...<span class='msg-tooltip'>* m4/guix.m4 (GUIX_CHECK_GUILE_SSH): Fix spelling of parameter.
(GUIX_CHECK_FILE_NAME_LIMITS): Fix spelling of maximum.

Change-Id: I93c80441393622a4bc06daa475eee13874cca527
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2023-03-16 12:37:03 +0100'>2023-03-16</span></td><td><a href='/guix/commit/m4?id=8e3dfb3d6dfc0f19bd9a9f9b163f0f3d7dccc865'>build: Correct guix_system on musl libc distros.</a><span class='msg-avail'>...<span class='msg-tooltip'>* m4/guix.m4 (GUIX_SYSTEM_TYPE): Add linux-musl* case. This prevents
the macro from mis-parsing the host OS, which causes breakage when
building from source.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>Antero Mejr</td></tr>