build: Fix out-of-tree make.

* doc/local.mk (lang_to_texinfo): Refer to .texi files using srcdir.
(xref_command): Reference pre-inst-env using builddir.
($(srcdir)/%D%/guix.%.texi):
($(srcdir)/%D%/guix-cookbook.%.texi):
($(srcdir)/%D%/contributing.%.texi): Refer to source files using srcdir.
* nix/local.mk (etc/guix-gc.timer): Use the name of the prerequisite,
not just its file name.

Change-Id: I247bcd873c8355d0eae07870ec849d2eb8cfa6c5
Signed-off-by: Ludovic Courtès <ludo@gnu.org>
Merges: #8267

1 files changed, 1 insertions, 1 deletions

diff --git a/nix/local.mk b/nix/local.mk
index 2c93670843c..9a529da0000 100644
--- a/nix/local.mk
+++ b/nix/local.mk
@@ -162,7 +162,7 @@ etc/guix-%.service: etc/guix-%.service.in	\
 etc/guix-gc.timer: etc/guix-gc.timer.in \
                          $(top_builddir)/config.status
         $(AM_V_GEN)$(MKDIR_P) "`dirname $@`";   \
-        cp "$@.in" "$@"
+        cp "$<" "$@"
 
 # The service script for sysvinit.
 sysvinitservicedir = $(sysconfdir)/init.d