From 64b0cc5bc40db052a4eff15c6d1ed8e1efafcd0d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <theophane.hufschmitt@tweag.io>
Date: Mon, 3 Apr 2023 15:13:11 +0200
Subject: [PATCH 1/2] Make `nix-collect-garbage -d` look into more places

Make it look into the new-style profiles dir, the old-style one, and the
target of `~/.nix-profile` to be sure that we don't miss anything
---
 src/nix-collect-garbage/nix-collect-garbage.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/nix-collect-garbage/nix-collect-garbage.cc b/src/nix-collect-garbage/nix-collect-garbage.cc
index 3cc57af4e..cb1f42e35 100644
--- a/src/nix-collect-garbage/nix-collect-garbage.cc
+++ b/src/nix-collect-garbage/nix-collect-garbage.cc
@@ -77,7 +77,12 @@ static int main_nix_collect_garbage(int argc, char * * argv)
             return true;
         });
 
-        if (removeOld) removeOldGenerations(profilesDir());
+        if (removeOld) {
+            std::set<Path> dirsToClean = {
+                profilesDir(), settings.nixStateDir + "/profiles", dirOf(getDefaultProfile())};
+            for (auto & dir : dirsToClean)
+                removeOldGenerations(dir);
+        }
 
         // Run the actual garbage collector.
         if (!dryRun) {

From e97e9e9f0055d02c16a3dc8e7891c06d643aaf82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Th=C3=A9ophane=20Hufschmitt?=
 <theophane.hufschmitt@tweag.io>
Date: Mon, 15 May 2023 11:58:49 +0200
Subject: [PATCH 2/2] test the garbage collection with the old profile dir

Regression test for https://github.com/NixOS/nix/issues/8294
---
 tests/gc.sh | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/tests/gc.sh b/tests/gc.sh
index 98d6cb032..95669e25c 100644
--- a/tests/gc.sh
+++ b/tests/gc.sh
@@ -52,9 +52,7 @@ rmdir $NIX_STORE_DIR/.links
 rmdir $NIX_STORE_DIR
 
 ## Test `nix-collect-garbage -d`
-# `nix-env` doesn't work with CA derivations, so let's ignore that bit if we're
-# using them
-if [[ -z "${NIX_TESTS_CA_BY_DEFAULT:-}" ]]; then
+testCollectGarbageD () {
     clearProfiles
     # Run two `nix-env` commands, should create two generations of
     # the profile
@@ -66,4 +64,17 @@ if [[ -z "${NIX_TESTS_CA_BY_DEFAULT:-}" ]]; then
     # left
     nix-collect-garbage -d
     [[ $(nix-env --list-generations | wc -l) -eq 1 ]]
+}
+# `nix-env` doesn't work with CA derivations, so let's ignore that bit if we're
+# using them
+if [[ -z "${NIX_TESTS_CA_BY_DEFAULT:-}" ]]; then
+    testCollectGarbageD
+
+    # Run the same test, but forcing the profiles at their legacy location under
+    # /nix/var/nix.
+    #
+    # Regression test for #8294
+    rm ~/.nix-profile
+    ln -s $NIX_STATE_DIR/profiles/per-user/me ~/.nix-profile
+    testCollectGarbageD
 fi