shell.nix: automatically configure b4

This will allow people who just want to test one patch series to skip
an annoying setup process.  To be honest, I'm not sure if it's worth
keeping the documentation about manually setting it up.  I'm worried
it'll just confuse people.  But I'm keeping it for now.  We can remove
it later.

Signed-off-by: Alyssa Ross <hi@alyssa.is>

1 files changed, 9 insertions, 1 deletions

diff --git a/shell.nix b/shell.nix
index 4dc8558..77deb2c 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,8 +1,16 @@
 # SPDX-FileCopyrightText: 2022 Alyssa Ross <hi@alyssa.is>
+# SPDX-FileCopyrightText: 2022 Unikie
 # SPDX-License-Identifier: MIT
 
 { config ? import nix/eval-config.nix {} }: with config.pkgs;
 
 mkShell {
-  nativeBuildInputs = [ reuse rustfmt ];
+  nativeBuildInputs = [ b4 reuse rustfmt ];
+
+  shellHook = ''
+    declare -igx GIT_CONFIG_COUNT
+    export "GIT_CONFIG_KEY_''${GIT_CONFIG_COUNT:-0}"=b4.midmask
+    export "GIT_CONFIG_VALUE_''${GIT_CONFIG_COUNT:-0}"=https://spectrum-os.org/lists/archives/spectrum-devel/%s
+    GIT_CONFIG_COUNT+=1
+  '';
 }