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
lass='active' href='/guix/log/gnu/system/examples/asus-c201.tmpl'>log</a><a href='/guix/tree/gnu/system/examples/asus-c201.tmpl?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>tree</a><a href='/guix/commit/gnu/system/examples/asus-c201.tmpl?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>commit</a><a href='/guix/diff/gnu/system/examples/asus-c201.tmpl?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/gnu/system/examples/asus-c201.tmpl'>
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<div class='path'>path: <a href='/guix/log/?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>root</a>/<a href='/guix/log/gnu?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>gnu</a>/<a href='/guix/log/gnu/system?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>system</a>/<a href='/guix/log/gnu/system/examples?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>examples</a>/<a href='/guix/log/gnu/system/examples/asus-c201.tmpl?id=049d53ee393abb072af9208ce37ec29e57c8fe96'>asus-c201.tmpl</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/system/examples/asus-c201.tmpl?id=049d53ee393abb072af9208ce37ec29e57c8fe96&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-03-22 20:55:37 -0700'>2020-03-22</span></td><td><a href='/guix/commit/gnu/system/examples/asus-c201.tmpl?id=37f8c50cdc2e99189c74999319f3a1854d419546'>gnu: linux-libre-arm-veyron: Deprecate package.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/packages/linux (linux-libre-arm-veyron): Mark as deprecated package.
  (kernel-config-veyron): Remove obsolete function.
* gnu/system/examples/asus-c201.tmpl: Update to use linux-libre-arm-generic.
* gnu/packages/aux-files/linux-libre/5.4-arm-veyron.conf: Delete file.
* Makefile.am (AUX_FILES): Update accordingly.
</span></span></td><td>Vagrant Cascadian</td></tr>