pkgs/build-support/setup-hooks/set-source-date-epoch-to-latest.sh

   1 updateSourceDateEpoch() {
   2     local path="$1"
   3
   4     # Get the last modification time of all regular files, sort them,
   5     # and get the most recent. Maybe we should use
   6     # https://github.com/0-wiz-0/findnewest here.
   7     local -a res=($(find "$path" -type f -not -newer "$NIX_BUILD_TOP/.." -printf '%T@ %p\0' \
   8                     | sort -n --zero-terminated | tail -n1 --zero-terminated | head -c -1))
   9     local time="${res[0]//\.[0-9]*/}" # remove the fraction part
  10     local newestFile="${res[1]}"
  11
  12     # Update $SOURCE_DATE_EPOCH if the most recent file we found is newer.
  13     if [ "${time:-0}" -gt "$SOURCE_DATE_EPOCH" ]; then
  14         echo "setting SOURCE_DATE_EPOCH to timestamp $time of file $newestFile"
  15         export SOURCE_DATE_EPOCH="$time"
  16
  17         # Warn if the new timestamp is too close to the present. This
  18         # may indicate that we were being applied to a file generated
  19         # during the build, or that an unpacker didn't restore
  20         # timestamps properly.
  21         local now="$(date +%s)"
  22         if [ "$time" -gt $((now - 60)) ]; then
  23             echo "warning: file $newestFile may be generated; SOURCE_DATE_EPOCH may be non-deterministic"
  24         fi
  25     fi
  26 }
  27
  28 postUnpackHooks+=(_updateSourceDateEpochFromSourceRoot)
  29
  30 _updateSourceDateEpochFromSourceRoot() {
  31     if [ -n "$sourceRoot" ]; then
  32         updateSourceDateEpoch "$sourceRoot"
  33     fi
  34 }