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
='/guix/log/gnu/packages/datamash.scm'>log</a><a href='/guix/tree/gnu/packages/datamash.scm?id=33238b552000aa730d6e306df4fadbac2ad2db02'>tree</a><a href='/guix/commit/gnu/packages/datamash.scm?id=33238b552000aa730d6e306df4fadbac2ad2db02'>commit</a><a href='/guix/diff/gnu/packages/datamash.scm?id=33238b552000aa730d6e306df4fadbac2ad2db02'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/packages/datamash.scm'>
<input type='hidden' name='id' value='33238b552000aa730d6e306df4fadbac2ad2db02'/><select name='qt'>
<option value='grep'>log msg</option>
<option value='author'>author</option>
<option value='committer'>committer</option>
<option value='range'>range</option>
</select>
<input class='txt' type='search' size='10' name='q' value=''/>
<input type='submit' value='search'/>
</form>
</td></tr></table>
<div class='path'>path: <a href='/guix/log/?id=33238b552000aa730d6e306df4fadbac2ad2db02'>root</a>/<a href='/guix/log/gnu?id=33238b552000aa730d6e306df4fadbac2ad2db02'>gnu</a>/<a href='/guix/log/gnu/packages?id=33238b552000aa730d6e306df4fadbac2ad2db02'>packages</a>/<a href='/guix/log/gnu/packages/datamash.scm?id=33238b552000aa730d6e306df4fadbac2ad2db02'>datamash.scm</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/gnu/packages/datamash.scm?id=33238b552000aa730d6e306df4fadbac2ad2db02&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-12-23 16:37:51 +0200'>2018-12-23</span></td><td><a href='/guix/commit/gnu/packages/datamash.scm?id=b83ddd03d961ea0a0cf75eb6649ecec4fbd4fb94'>gnu: datamash: Update to 1.4.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/datamash.scm (datamash): Update to 1.4.
[source]: Remove patch.
* gnu/packages/patches/datamash-arm-tests.patch: Remove file.
* gnu/local.mk (dist_patch_DATA): Remove it.
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2018-04-12 22:55:51 -0500'>2018-04-12</span></td><td><a href='/guix/commit/gnu/packages/datamash.scm?id=de7f234a3a3e583e7af832e956b44455c71dc5cb'>gnu: datamash: Fix tests on ARM systems.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/patches/datamash-arm-tests.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/datamash.scm (datamash)[source]: Use it.
</span></span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2018-03-18 00:02:06 +0100'>2018-03-18</span></td><td><a href='/guix/commit/gnu/packages/datamash.scm?id=80f565d3137eceb479b8f7d39c26e00385dd65f6'>gnu: datamash: Update to 1.3.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/datamash.scm (datamash): Update to 1.3.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-08-24 10:35:00 +0300'>2017-08-24</span></td><td><a href='/guix/commit/gnu/packages/datamash.scm?id=c47048c328843bcc26772bd6c96d03962972b173'>gnu: datamash: Update to 1.2.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/datamash.scm (datamash): Update to 1.2.
</span></span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2017-01-20 19:35:47 +0100'>2017-01-20</span></td><td><a href='/guix/commit/gnu/packages/datamash.scm?id=ff99fe6505b3831d9b563c584552674280b6c671'>gnu: datamash: Update to 1.1.1.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/datamash.scm (datamash): Update to 1.1.1.
</span></span></td><td>Marius Bakke</td></tr>