From c904eddb9165e434a4f66cc9b15124ea7a99bd19 Mon Sep 17 00:00:00 2001
From: tobtoht <tob@featherwallet.org>
Date: Tue, 12 Mar 2024 14:29:32 +0100
Subject: [PATCH] guix: use a fixed timestamp for depends packages

---
 contrib/guix/guix-build       | 8 ++++----
 contrib/guix/libexec/build.sh | 9 ++++++++-
 2 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/contrib/guix/guix-build b/contrib/guix/guix-build
index 93f624d..bff585f 100755
--- a/contrib/guix/guix-build
+++ b/contrib/guix/guix-build
@@ -199,7 +199,7 @@ host_to_commonname() {
     esac
 }
 
-SOURCE_DATE_EPOCH="1701896000"
+COMMIT_TIMESTAMP="$(git -c log.showSignature=false log --format=%at -1)"
 
 # Precious directories are those which should not be cleaned between successive
 # guix builds
@@ -322,7 +322,7 @@ for host in $HOSTS; do
         # shellcheck disable=SC2030
 cat << EOF
 INFO: Building ${VERSION:?not set} for platform triple ${HOST:?not set}:
-      ...using reference timestamp: ${SOURCE_DATE_EPOCH:?not set}
+      ...using commit timestamp: ${COMMIT_TIMESTAMP:?not set}
       ...running at most ${JOBS:?not set} jobs
       ...from worktree directory: '${PWD}'
           ...bind-mounted in container to: '/feather'
@@ -434,7 +434,7 @@ EOF
                                  -- env HOST="$HOST" \
                                         DISTNAME="$DISTNAME" \
                                         JOBS="$JOBS" \
-                                        SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:?unable to determine value}" \
+                                        COMMIT_TIMESTAMP="${COMMIT_TIMESTAMP:?unable to determine value}" \
                                         ${V:+V=1} \
                                         ${SOURCES_PATH:+SOURCES_PATH="$SOURCES_PATH"} \
                                         ${BASE_CACHE:+BASE_CACHE="$BASE_CACHE"} \
@@ -465,7 +465,7 @@ EOF
                                          ${SUBSTITUTE_URLS:+--substitute-urls="$SUBSTITUTE_URLS"} \
                                          ${ADDITIONAL_GUIX_COMMON_FLAGS} ${ADDITIONAL_GUIX_ENVIRONMENT_FLAGS} \
                                          -- env DISTNAME="$DISTNAME" \
-                                                SOURCE_DATE_EPOCH="${SOURCE_DATE_EPOCH:?unable to determine value}" \
+                                                SOURCE_DATE_EPOCH="${COMMIT_TIMESTAMP:?unable to determine value}" \
                                                 VERSION="$VERSION" \
                                          bash -c "cd /feather && \
                                                   bash contrib/flatpak/make_flatpak.sh"
diff --git a/contrib/guix/libexec/build.sh b/contrib/guix/libexec/build.sh
index e53e9cc..e5c22e9 100755
--- a/contrib/guix/libexec/build.sh
+++ b/contrib/guix/libexec/build.sh
@@ -36,7 +36,7 @@ Required environment variables as seen inside the container:
     DIST_ARCHIVE_BASE: ${DIST_ARCHIVE_BASE:?not set}
     DISTNAME: ${DISTNAME:?not set}
     HOST: ${HOST:?not set}
-    SOURCE_DATE_EPOCH: ${SOURCE_DATE_EPOCH:?not set}
+    COMMIT_TIMESTAMP: ${COMMIT_TIMESTAMP:?not set}
     JOBS: ${JOBS:?not set}
     DISTSRC: ${DISTSRC:?not set}
     OUTDIR: ${OUTDIR:?not set}
@@ -46,6 +46,9 @@ EOF
 ACTUAL_OUTDIR="${OUTDIR}"
 OUTDIR="${DISTSRC}/output"
 
+# Use a fixed timestamp for depends builds so hashes match across commits that don't make changes to the build system
+export SOURCE_DATE_EPOCH=1397818193
+
 #####################
 # Environment Setup #
 #####################
@@ -230,6 +233,10 @@ make -C contrib/depends --jobs="$JOBS" HOST="$HOST" \
 # Source Tarball Building #
 ###########################
 
+# Use COMMIT_TIMESTAMP for the source and release binary archives
+export SOURCE_DATE_EPOCH=${COMMIT_TIMESTAMP}
+export TAR_OPTIONS="--owner=0 --group=0 --numeric-owner --mtime='@${SOURCE_DATE_EPOCH}' --sort=name"
+
 GIT_ARCHIVE="${DIST_ARCHIVE_BASE}/${DISTNAME}.tar.gz"
 
 # Create the source tarball if not already there