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)" \
 <option value='koszko' selected='selected'>koszko</option>
<option value='koszko-scripts'>koszko-scripts</option>
</select> <input type='submit' value='switch'/></form></td></tr>
<tr><td class='sub'>Wojtek's customized Guix</td><td class='sub right'></td></tr></table>
<table class='tabs'><tr><td>
<a href='/guix/about/'>about</a><a href='/guix/'>summary</a><a href='/guix/refs/?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>refs</a><a class='active' href='/guix/log/tests/rpm.scm'>log</a><a href='/guix/tree/tests/rpm.scm?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>tree</a><a href='/guix/commit/tests/rpm.scm?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>commit</a><a href='/guix/diff/tests/rpm.scm?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/rpm.scm'>
<input type='hidden' name='id' value='97256395df705dd9f9c76d18a302cbce8f94bcfe'/><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=97256395df705dd9f9c76d18a302cbce8f94bcfe'>root</a>/<a href='/guix/log/tests?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>tests</a>/<a href='/guix/log/tests/rpm.scm?id=97256395df705dd9f9c76d18a302cbce8f94bcfe'>rpm.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/rpm.scm?id=97256395df705dd9f9c76d18a302cbce8f94bcfe&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2023-02-19 21:13:23 -0500'>2023-02-19</span></td><td><a href='/guix/commit/tests/rpm.scm?id=598f4c509bbfec2b983a8ee246cce0a0fe45ec7f'>pack: Add RPM format.</a><span class='msg-avail'>...<span class='msg-tooltip'>* guix/rpm.scm: New file.
* guix/scripts/pack.scm (rpm-archive): New procedure.
(%formats): Register it.
(show-formats): Add it.
(guix-pack): Register supported extra-options for the rpm format.
* tests/pack.scm (rpm-for-tests): New variable.
("rpm archive can be installed/uninstalled"): New test.
* tests/rpm.scm: New test.
* doc/guix.texi (Invoking guix pack): Document it.
</span></span></td><td>Maxim Cournoyer</td></tr>