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
@@ -56,7 +56,7 @@ readonly SOURCEDIR=icecat-${FFVERSION}
 # debug/shell options
 readonly DEVEL=0
 set -euo pipefail
-(( DEVEL )) && set -x
+set -x
 
 
 ###############################################################################
@@ -455,7 +455,7 @@ configure_search()
 
 
     # 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()
@@ -837,12 +837,12 @@ 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
@@ -854,4 +854,4 @@ prepare_macos_packaging
 configure_extensions
 configure_onboarding
 apply_bugfixes
-finalize_sourceball
+# finalize_sourceball