Install everything in PREFIX, set EXTRA_PATH to find it there.

--- ./Makefile.in~	2016-02-06 01:29:16.595090365 +0100
+++ ./Makefile.in	2016-02-06 09:29:04.286008931 +0100
@@ -133,9 +133,9 @@
 # require for testing here (like TCLX_LIBRARY).
 #========================================================================

-EXTRA_PATH	= $(top_builddir):$(TCL_BIN_DIR)
+EXTRA_PATH	= $(top_builddir):$(TCL_BIN_DIR):$(libdir)
 #EXTRA_PATH     = $(top_builddir):$(TCL_BIN_DIR):$(TK_BIN_DIR)
-TCLLIBPATH      = $(top_builddir)
+TCLLIBPATH      = $(pkglibdir)
 TCLSH_ENV	= TCL_LIBRARY=`@CYGPATH@ $(TCL_SRC_DIR)/library` \
 		  @LD_LIBRARY_PATH_VAR@="$(EXTRA_PATH):$(@LD_LIBRARY_PATH_VAR@)" \
 		  PATH="$(EXTRA_PATH):$(PATH)" \
 bmit();'>
<option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
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<div class='path'>path: <a href='/guix/log/?id=031f705a438e25af3b0fd1fe1b6453c4531608e0'>root</a>/<a href='/guix/log/tests?id=031f705a438e25af3b0fd1fe1b6453c4531608e0'>tests</a>/<a href='/guix/log/tests/guix-lint.sh?id=031f705a438e25af3b0fd1fe1b6453c4531608e0'>guix-lint.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-lint.sh?id=031f705a438e25af3b0fd1fe1b6453c4531608e0&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-09-28 21:06:36 -0500'>2020-09-28</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=d8934360d2453a403b5433e71d09188e4ed23b57'>tests: Simplify shell exit status negation;</a><span class='msg-avail'>...<span class='msg-tooltip'>* tests/guix-archive.sh, tests/guix-build-branch.sh, tests/guix-build.sh,
tests/guix-daemon.sh, tests/guix-download.sh, tests/guix-environment.sh,
tests/guix-gc.sh, tests/guix-git-authenticate.sh, tests/guix-graph.sh,
tests/guix-hash.sh, tests/guix-lint.sh, tests/guix-pack-relocatable.sh,
tests/guix-pack.sh, tests/guix-package-aliases.sh, tests/guix-package-net.sh,
tests/guix-package.sh: Use the shell '!' keyword to negate command exit status
in place of 'if ...; then false; else true; fi'
</span></span></td><td>Eric Bavier</td></tr>
<tr><td><span title='2020-08-23 23:05:16 +0200'>2020-08-23</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=d10474c38d58bdc676e64336769dc2e00cdfa8ed'>lint: formatting: Gracefully handle relative file names.</a><span class='msg-avail'>...<span class='msg-tooltip'>Fixes &lt;https://bugs.gnu.org/42543&gt;.
Reported by Jack Hill &lt;jackhill@jackhill.us&gt;.

* guix/lint.scm (check-formatting): Always return a list (previously we
would return #f when 'search-path' returns #f).  Check whether
LOCATION's file is a relative file name.  Return a warning if not.
* tests/guix-lint.sh: Add test.
</span></span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2019-12-08 23:14:03 +0100'>2019-12-08</span></td><td><a href='/guix/commit/tests/guix-lint.sh?id=7282f9496793227d7ac6f902976aecb663068ec1'>lint: Add '--load-path' option.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/scripts/lint.scm (%options): Add '--load-path' option.
* doc/guix.texi: Document it.
* tests/guix-lint.sh: Test it.

Signed-off-by: Ludovic Courtès &lt;ludo@gnu.org&gt;
</span></span></td><td>zimoun</td></tr>