Make some of the changes needed to the 'makeicecat' script, to allow it to run
in a snippet without network access.  After this patch is applied, some
additional changes will be made using 'substitute*'.

diff --git a/makeicecat b/makeicecat
index bf2b7a6..bc3b19b 100755
--- a/makeicecat
+++ b/makeicecat
@@ -58,7 +58,7 @@ readonly SOURCEDIR=icecat-${FFVERSION}
 # debug/shell options
 readonly DEVEL=0
 set -euo pipefail
-(( DEVEL )) && set -x
+set -x
 
 
 ###############################################################################
@@ -459,7 +459,7 @@ configure_search()
     sed 's|ddg@|ddg-html@|' -i browser/components/search/extensions/ddg-html/manifest.json
 
     # Process various JSON pre-configuration dumps.
-    python3 ../../tools/process-json-files.py . browser/components/extensions/schemas/
+    python3 "${DATADIR}"/../tools/process-json-files.py . browser/components/extensions/schemas/
 }
 
 configure_mobile()
@@ -855,12 +855,12 @@ finalize_sourceball()
 # entry point
 ###############################################################################
 
-validate_env || exit 1
-prepare_env
-fetch_source
-verify_sources
-extract_sources
-fetch_l10n
+# validate_env || exit 1
+# prepare_env
+# fetch_source
+# verify_sources
+# extract_sources
+# fetch_l10n
 apply_patches
 configure
 configure_search
@@ -872,4 +872,4 @@ prepare_macos_packaging
 configure_extensions
 configure_onboarding
 apply_bugfixes
-finalize_sourceball
+# finalize_sourceball
'>diff</a></td><td class='form'><form class='right' method='get' action='/guix/log/tests/cache.scm'>
<input type='hidden' name='id' value='2afc79b51d0956e5834e81a70692a35cd83e4e87'/><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=2afc79b51d0956e5834e81a70692a35cd83e4e87'>root</a>/<a href='/guix/log/tests?id=2afc79b51d0956e5834e81a70692a35cd83e4e87'>tests</a>/<a href='/guix/log/tests/cache.scm?id=2afc79b51d0956e5834e81a70692a35cd83e4e87'>cache.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/cache.scm?id=2afc79b51d0956e5834e81a70692a35cd83e4e87&amp;showmsg=1'>Expand</a>)</th><th class='left'>Author</th></tr>
<tr><td><span title='2020-03-22 16:49:47 +0100'>2020-03-22</span></td><td><a href='/guix/commit/tests/cache.scm?id=9acacb71c958218fd69cf0fb9df0b439a980a0f2'>Remove workaround for 'time-monotonic' in Guile 2.2.2.</a><span class='msg-avail'>...<span class='msg-tooltip'>This is a followup to e688c2df3924423b67892cc9939ca099c729d1cb.

* build-aux/hydra/evaluate.scm &lt;top level&gt;: Remove 'time-monotonic'
definition.
* guix/cache.scm: Likewise.
* guix/progress.scm: Likewise.
* guix/scripts/substitute.scm: Likewise.
* guix/scripts/weather.scm: Likewise.
* tests/cache.scm: Likewise.
</span></span></td><td>Ludovic Courtès</td></tr>