Track committer additions with git history

After #31, people who
received commit access since a year ago were tracked with the date of
commit bit reception.

While this works, it's not necessary in the long term, because the git
history will keep track of when commit bits are given.

This change starts using the commit history when possible, which allows
avoiding the need for adding addition dates for new committers.

Author: infinisil

.github/workflows/retire.yml

@@ -34,6 +34,8 @@ jobs:
         uses: actions/checkout@v4
         with:
           token: ${{ steps.app-token.outputs.token }}
+          # Fetch full history to determine when committers were added
+          fetch-depth: 0
       - name: Run script
         # One month plus a bit of leeway
         run: scripts/retire.sh NixOS nixpkgs nixpkgs-committers members "yesterday 1 month ago"

members/Enzime

@@ -1 +0,0 @@
-2025-08-20

members/LordGrimmauld

@@ -1 +0,0 @@
-2025-08-20

members/MattSturgeon

@@ -1 +0,0 @@
-2025-08-20

members/SigmaSquadron

@@ -1 +0,0 @@
-2025-08-20

members/jmbaur

@@ -1 +0,0 @@
-2025-08-20

members/m1cr0man

@@ -1 +0,0 @@
-2025-08-20

scripts/retire.sh

@@ -37,9 +37,31 @@ DIR=${4:-$(usage)}
 NOTICE_CUTOFF=${5:-$(usage)}
 
 mainBranch=$(git branch --show-current)
-newCutoff=$(date --date="1 year ago" +%s)
 noticeCutoff=$(date --date="$NOTICE_CUTOFF" +%s)
 
+# People that received the commit bit after this date won't be retired
+newCutoff=$(date --date="1 year ago" +%s)
+
+# We need to know when people received their commit bit to avoid retiring them within the first year.
+# For now this is done either with the git creation date of the file, or its contents:
+#
+# | commit bit reception date  | file creation date | file contents  |
+# | -------------------------- | ------------------ | -------------- |
+# | A)         -∞ - 2024-10-06 | 2025-07-08         | empty          |
+# | B) 2024-10-07 - 2025-04-22 | 2025-07-08         | reception date |
+# | C) 2025-08-13 - ∞          | reception date     | empty          |
+#
+# After 2026-04-23 (one year after C started), the file creation date
+# for all first-year committers will match the reception date,
+# while everybody else will have been a committer for more than one year.
+# This means the code can then be simplified to just
+# check if the file creation date is in the last year.
+#
+# For now however, the code needs to check if the file creation date
+# is before 2025-07-09 to distinguish between periods A and C,
+# so we hardcode that date for the code to use.
+createdOnReceptionEpoch=$(date --date=2025-07-09 +%s)
+
 if [[ -z "${PROD:-}" ]]; then
   tmp=$(git rev-parse --show-toplevel)/.tmp
   rm -rf "$tmp"
@@ -54,12 +76,30 @@ mkdir -p "$DIR"
 cd "$DIR"
 for login in *; do
 
-  # Don't remove people that have been added recently
-  if [[ -s "$login" ]]; then
-    epochAdded=$(date --date="$(<"$login")" +%s)
-    if (( newCutoff < epochAdded )); then
-      continue
+  # Figure out when this person received the commit bit
+  # Get the unix epoch of the first commit that touched this file
+  # --first-parent is important to get the time of when the main branch was changed
+  fileCommitEpoch=$(git log --reverse --first-parent --format=%cd --date=unix -- "$login" | head -1)
+  if (( fileCommitEpoch < createdOnReceptionEpoch )); then
+    # If it was created before creation actually matched the reception date
+    # This branch can be removed after 2026-04-23
+
+    if [[ -s "$login" ]]; then
+      # If the file is non-empty it indicates an explicit reception date
+      receptionEpoch=$(date --date="$(<"$login")" +%s)
+    else
+      # Otherwise they received the commit bit more than a year ago (start of unix epoch, 1970)
+      receptionEpoch=0
     fi
+  else
+    # Otherwise creation matches reception
+    receptionEpoch=$fileCommitEpoch
+  fi
+
+  # If the commit bit was received after the cutoff date, don't retire in any case
+  if (( newCutoff < receptionEpoch )); then
+    log "$login became a committer less than 1 year ago, skipping retirement check"
+    continue
   fi
 
   trace gh api -X GET /repos/"$ORG"/"$ACTIVITY_REPO"/activity \

scripts/sync.sh

@@ -17,8 +17,7 @@ gh api /orgs/"$ORG"/teams/"$TEAM"/members --paginate --jq '.[].login' |
     if [[ -f "$DIR/$login" ]]; then
       mv "$DIR/$login" "$DIR.new"
     else
-      # Keep track of when the user was added
-      date +%F > "$DIR.new/$login"
+      touch "$DIR.new/$login"
     fi
   done