From 0d49f01fbbe28c40095753f3764b74589d40e89b Mon Sep 17 00:00:00 2001
From: Dmitry Ivankov <boltzmannrain@gmail.com>
Date: Mon, 20 Nov 2023 01:49:45 +0100
Subject: [PATCH] bazel_6: fix: make patched bash a native binary

https://hydra.nixos.org/build/240805256/nixlog/1
https://hydra.nixos.org/build/240805170/nixlog/2
Failure is a bit obscured but long story short, a script within
bazel gets custom nixpkgs shebang which in turn makes shell run
in POSIX-compatible mode. Bazel expects bash in non-POSIX mode
and osx-specific script starts to fail due to `set -e` and subshell
interaction differences in those modes (sub-shells and functions
suddently start inheriting `set -e` and fail to produce desired
output). More debug info is available in #267670

Shell scripts aren't guaranteed to work as interpreters in shebang.
In particular thin shell wrappers aren't shebang-ready on MacOS.
It may work sometimes depending on what exactly would try to execute
a script with such shebang, but generally it's not guaranteed to work.
See #124556

Bash wrapper was introduced in #266847 and so far seems like the
issue only affects darwin builds: hydra failure is in osx-specific
script, also shebang issue is usually darwin-specific.

Let's wrap it as a native binary to make it shebang-compatible.

The wrapper is only currently added to `bazel_6` so no need for
changes in other versions.

ZHF: #265948
---
 .../tools/build-managers/bazel/bazel_6/default.nix | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/tools/build-managers/bazel/bazel_6/default.nix b/pkgs/development/tools/build-managers/bazel/bazel_6/default.nix
index 35f1c9980b4db8a..9aee8c394f5c10f 100644
--- a/pkgs/development/tools/build-managers/bazel/bazel_6/default.nix
+++ b/pkgs/development/tools/build-managers/bazel/bazel_6/default.nix
@@ -23,6 +23,7 @@
 , substituteAll
 , writeTextFile
 , writeShellApplication
+, makeBinaryWrapper
 }:
 
 let
@@ -129,7 +130,7 @@ let
 
   defaultShellPath = lib.makeBinPath defaultShellUtils;
 
-  bashWithDefaultShellUtils = writeShellApplication {
+  bashWithDefaultShellUtilsSh = writeShellApplication {
     name = "bash";
     runtimeInputs = defaultShellUtils;
     text = ''
@@ -140,6 +141,17 @@ let
     '';
   };
 
+  # Sript-based interpreters in shebangs aren't guaranteed to work,
+  # especially on MacOS. So let's produce a binary
+  bashWithDefaultShellUtils = stdenv.mkDerivation {
+    name = "bash";
+    src = bashWithDefaultShellUtilsSh;
+    nativeBuildInputs = [ makeBinaryWrapper ];
+    buildPhase = ''
+      makeWrapper ${bashWithDefaultShellUtilsSh}/bin/bash $out/bin/bash
+    '';
+  };
+
   platforms = lib.platforms.linux ++ lib.platforms.darwin;
 
   system = if stdenv.hostPlatform.isDarwin then "darwin" else "linux";