Skip tests that rely on the `amhello' tarball that comes with Automake.
That tarball's `configure' uses #!/bin/sh, but we can't easily patch it.

diff --git a/t/amhello-binpkg.sh b/t/amhello-binpkg.sh
index fa88cc6..d988cee 100755
--- a/t/amhello-binpkg.sh
+++ b/t/amhello-binpkg.sh
@@ -17,6 +17,7 @@
 # Test an example from the manual about the 'amhello' package:
 # using DESTDIR to build simple, no-frills binary packages.
 
+exit 77
 am_create_testdir=empty
 . ./defs || exit 1
 
diff --git a/t/amhello-cflags.sh b/t/amhello-cflags.sh
index 666011f..2a95e3c 100755
--- a/t/amhello-cflags.sh
+++ b/t/amhello-cflags.sh
@@ -18,6 +18,7 @@
 # using VPATH builds to configure the same package with different
 # options.
 
+exit 77
 am_create_testdir=empty
 required=gcc
 . ./defs || exit 1
diff --git a/t/amhello-cross-compile.sh b/t/amhello-cross-compile.sh
index 708abda..2ee4292 100755
--- a/t/amhello-cross-compile.sh
+++ b/t/amhello-cross-compile.sh
@@ -17,6 +17,7 @@
 # Test an example from the manual about the 'amhello' package:
 # cross-compiling a package from Linux/Unix to MinGW.
 
+exit 77
 am_create_testdir=empty
 required=i586-mingw32msvc-gcc
 . ./defs || exit 1
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<div class='path'>path: <a href='/guix/log/?id=1d6d048df9eda22a0544cb034606176c8f8fd5a9'>root</a>/<a href='/guix/log/tests?id=1d6d048df9eda22a0544cb034606176c8f8fd5a9'>tests</a>/<a href='/guix/log/tests/guix-time-machine.sh?id=1d6d048df9eda22a0544cb034606176c8f8fd5a9'>guix-time-machine.sh</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/tests/guix-time-machine.sh?id=1d6d048df9eda22a0544cb034606176c8f8fd5a9&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2024-03-11 22:12:34 +0100'>2024-03-11</span></td><td><a href='/guix/commit/tests/guix-time-machine.sh?id=a26bce55e60aa3444c4378d3996f3aa41b9661e9'>time-machine: Allow time travels to v0.16.0.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/time-machine.scm (%oldest-possible-commit): Change to
v0.16.0.
* tests/guix-time-machine.sh: Adjust comment.

Change-Id: I9ad82bd45fee0d172b5348a8ae16e990338a3a97
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-11-05 23:23:23 +0100'>2023-11-05</span></td><td><a href='/guix/commit/tests/guix-time-machine.sh?id=9f05fbb67d0de4d577c21a6fb6888cb6be67cd12'>tests: Make ‘guix time-machine’ test effective.</a><span class='msg-avail'>...<span class='msg-tooltip'>The test as added in 79ec651a286c71a3d4c72be33a1f80e76a560031 had no
effect: first because ‘guix time-machine --commit=X’, not followed by a
command, does nothing, and second because the “! COMMAND” shell stanza
does not have the desired effect (see &lt;https://issues.guix.gnu.org/62406&gt;).

This change rewrites the test to make it effective.

* tests/guix-time-machine.sh: Rewrite.

Change-Id: Ib44a11331c8625e346139a236cffa699cdbd02f2
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2023-08-16 21:34:13 -0400'>2023-08-16</span></td><td><a href='/guix/commit/tests/guix-time-machine.sh?id=79ec651a286c71a3d4c72be33a1f80e76a560031'>scripts: time-machine: Error when attempting to visit too old commits.</a><span class='msg-avail'>...<span class='msg-tooltip'>* doc/guix.texi (Invoking guix time-machine): Document limitation.
* guix/inferior.scm (cached-channel-instance): New VALIDATE-CHANNELS
argument.  Use it to validate channels when there are no cache hit.
* guix/scripts/time-machine.scm
(%options): Tag the given reference with 'tag-or-commit instead of 'commit.
(%oldest-possible-commit): New variable.
(guix-time-machine) &lt;validate-guix-channel&gt;: New nested procedure.  Pass it to
the 'cached-channel-instance' call.
* tests/guix-time-machine.sh: New test.
* Makefile.am (SH_TESTS): Register it.

Suggested-by: Simon Tournier &lt;zimon.toutoune@gmail.com&gt;
Reviewed-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
Reviewed-by: Simon Tournier &lt;zimon.toutoune@gmail.com&gt;
</span></span></td><td>Maxim Cournoyer</td></tr>