From bb77c561315544f013f7c3cedadc378ff40c62af Mon Sep 17 00:00:00 2001
From: jcardozo-eth <131674798+jcardozo-eth@users.noreply.github.com>
Date: Wed, 15 Jul 2026 19:29:15 +0200
Subject: [PATCH] ci(github): strip ANSI colour codes from the environment diff
 comment

nix store diff-closures colours the size delta even when stdout is not a
TTY, so the colour escape codes leaked into the PR comment and rendered
as raw control codes (e.g. ^[[31;1m93.9 KiB^[[0m). Pipe the diff through
sed to strip the SGR codes before it reaches the comment body.
---
 .github/workflows/environment-diff.yml | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/environment-diff.yml b/.github/workflows/environment-diff.yml
index e68042e..58c47fe 100644
--- a/.github/workflows/environment-diff.yml
+++ b/.github/workflows/environment-diff.yml
@@ -60,7 +60,11 @@ jobs:
             # Empty file: the closures are identical (no effective change).
             : > diff.txt
           else
-            nix store diff-closures ./result-base ./result-head > diff.txt
+            # Strip ANSI colour codes: diff-closures colours the size delta
+            # even when stdout is not a TTY, and the escape codes would
+            # render as raw control codes inside the Markdown comment.
+            nix store diff-closures ./result-base ./result-head \
+              | sed -E 's/\x1b\[[0-9;]*m//g' > diff.txt
           fi
 
       - name: Upsert the PR comment