separateDebugInfo: compress it by default

Using zlib should be cheap enough and save lots of HDD space.
Case study (glib): 11 MB -> 4 MB.

1 files changed, 8 insertions, 1 deletions

diff --git a/pkgs/build-support/setup-hooks/separate-debug-info.sh b/pkgs/build-support/setup-hooks/separate-debug-info.sh
index 317f13beffdd..1f27cb0ffd61 100644
--- a/pkgs/build-support/setup-hooks/separate-debug-info.sh
+++ b/pkgs/build-support/setup-hooks/separate-debug-info.sh
@@ -30,7 +30,14 @@ _separateDebugInfo() {
         # Extract the debug info.
         header "separating debug info from $i (build ID $id)"
         mkdir -p "$dst/${id:0:2}"
-        objcopy --only-keep-debug "$i" "$dst/${id:0:2}/${id:2}.debug"
+        objcopy --only-keep-debug "$i" "$dst/${id:0:2}/${id:2}.debug" --compress-debug-sections
         strip --strip-debug "$i"
     done
 }
+
+# - We might prefer to compress the debug info during link-time already,
+#   but our ld doesn't support --compress-debug-sections=zlib (yet).
+# - Debug info may cause due to excessive memory usage during linking.
+#   Using -Wa,--compress-debug-sections should help with that;
+#   further interesting information: https://gcc.gnu.org/wiki/DebugFission
+