We want to allow builds in chroots that lack /bin/sh.  Thus, system(3)
and popen(3) need to be tweaked to use the right shell.  For the bootstrap
glibc, we just use whatever `sh' can be found in $PATH.  The final glibc
instead uses the hard-coded absolute file name of `bash'.

--- a/sysdeps/posix/system.c
+++ b/sysdeps/posix/system.c
@@ -140,7 +140,7 @@ do_system (const char *line)
   __posix_spawnattr_setflags (&spawn_attr,
 			      POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK);
 
-  status = __posix_spawn (&pid, SHELL_PATH, 0, &spawn_attr,
+  status = posix_spawnp (&pid, SHELL_NAME, 0, &spawn_attr,
 			  (char *const[]){ (char*) SHELL_NAME,
 					   (char*) "-c",
 					   (char *) line, NULL },
--- a/libio/iopopen.c
+++ b/libio/iopopen.c
@@ -85,7 +85,7 @@ spawn_process (posix_spawn_file_actions_t *fa, FILE *fp, const char *command,
 	return false;
     }
 
-  if (__posix_spawn (&((_IO_proc_file *) fp)->pid, _PATH_BSHELL, fa, 0,
+  if (posix_spawnp (&((_IO_proc_file *) fp)->pid, "sh", fa, 0,
 		     (char *const[]){ (char*) "sh", (char*) "-c",
 		     (char *) command, NULL }, __environ) != 0)
     return false;

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<div class='path'>path: <a href='/guix/log/?id=f9dcc39ac106bd65df9e472bdabeb48303a4b18a'>root</a>/<a href='/guix/log/tests?id=f9dcc39ac106bd65df9e472bdabeb48303a4b18a'>tests</a>/<a href='/guix/log/tests/system.scm?id=f9dcc39ac106bd65df9e472bdabeb48303a4b18a'>system.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/tests/system.scm?id=f9dcc39ac106bd65df9e472bdabeb48303a4b18a&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2018-06-21 23:54:15 +0200'>2018-06-21</span></td><td><a href='/guix/commit/tests/system.scm?id=68a58775e071d4b0e000b93ad121b6e64d161b79'>system: Mapped devices needed for boot do not yield Shepherd services.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/31889&gt;.
Reported by Taylan Kammer &lt;taylanbayirli@gmail.com&gt;.

* gnu/system.scm (non-boot-file-system-service)[mapped-devices-for-boot]:
New variable.
Remove dependencies of FS that are members of MAPPED-DEVICES-FOR-BOOT.
(mapped-device-user): Rename to...
(mapped-device-users): ... this.  Use 'filter' instead of 'find'.
(operating-system-user-mapped-devices)
(operating-system-boot-mapped-devices): Use 'any
file-system-needed-for-boot?' instead of looking at the first user.
* tests/system.scm ("non-boot-file-system-service"): New test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2018-05-28 13:24:19 +0200'>2018-05-28</span></td><td><a href='/guix/commit/tests/system.scm?id=9ceeca0880248eee8c2796f5e6ebc172b95277f7'>system: Remove uses of the 'title' field of &lt;file-system&gt;.</a><span class='msg-avail'>...<span class='msg-tooltip'>* gnu/system/install.scm (installation-os): Remove uses of the 'title'
field of 'file-system'; use 'file-system-label' as appropriate.
* gnu/system/vm.scm (system-disk-image, system-qemu-image): Likewise.
* gnu/tests.scm (%simple-os): Likewise.
* gnu/tests/install.scm (%minimal-os, %minimal-extlinux-os)
(%minimal-os-on-vda, %separate-home-os, %separate-store-os)
(%raid-root-os, %encrypted-root-os, %btrfs-root-os): Likewise.
* gnu/build/shepherd.scm (default-mounts)[tmpfs]: Likewise.
* tests/guix-system.sh: Likewise.
* tests/system.scm (%root-fs): Likewise.
("operating-system-boot-mapped-devices, implicit dependency"): Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>