Merge pull request #256628 from alyssais/nix-prefetch-git-config

nix-prefetch-git: ignore global and user git config

nixos/doc/manual/release-notes/rl-2311.section.md

···
 
 - `himalaya` has been updated to `0.8.0`, which drops the native TLS support (in favor of Rustls) and add OAuth 2.0 support. See the [release note](https://github.com/soywod/himalaya/releases/tag/v0.8.0) for more details.
 
+- `nix-prefetch-git` now ignores global and user git config, to improve reproducibility.
+
 - The [services.caddy.acmeCA](#opt-services.caddy.acmeCA) option now defaults to `null` instead of `"https://acme-v02.api.letsencrypt.org/directory"`, to use all of Caddy's default ACME CAs and enable Caddy's automatic issuer fallback feature by default, as recommended by upstream.
 
 - The default priorities of [`services.nextcloud.phpOptions`](#opt-services.nextcloud.phpOptions) have changed. This means that e.g.

pkgs/build-support/fetchgit/nix-prefetch-git

···
     local rev="${3:-HEAD}"
 
     if [ -n "$fetchLFS" ]; then
-        tmpHomePath="$(mktemp -d "${TMPDIR:-/tmp}/nix-prefetch-git-tmp-home-XXXXXXXXXX")"
-        exit_handlers+=(remove_tmpHomePath)
-        HOME="$tmpHomePath"
         clean_git lfs install
     fi
 
···
 if test -z "$branchName"; then
     branchName=fetchgit
 fi
+
+tmpHomePath="$(mktemp -d "${TMPDIR:-/tmp}/nix-prefetch-git-tmp-home-XXXXXXXXXX")"
+exit_handlers+=(remove_tmpHomePath)
+HOME="$tmpHomePath"
+unset XDG_CONFIG_HOME
+export GIT_CONFIG_NOSYSTEM=1
 
 if test -n "$builder"; then
     test -n "$out" -a -n "$url" -a -n "$rev" || usage