From 33723434a888b7b9ce5a9b35dba2e77baf254109 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Sun, 7 Jul 2019 14:44:04 +0200
Subject: [PATCH] rustc: Add setup hook to set $CARGO_HOME

This works around 'failed to open:
/homeless-shelter/.cargo/.package-cache' with Rust 1.36 even when
we're using 'cargo --frozen'.
---
 pkgs/development/compilers/rust/rustc.nix     | 2 ++
 pkgs/development/compilers/rust/setup-hook.sh | 4 ++++
 2 files changed, 6 insertions(+)
 create mode 100644 pkgs/development/compilers/rust/setup-hook.sh

diff --git a/pkgs/development/compilers/rust/rustc.nix b/pkgs/development/compilers/rust/rustc.nix
index 056f17c43d72..66da4d33251a 100644
--- a/pkgs/development/compilers/rust/rustc.nix
+++ b/pkgs/development/compilers/rust/rustc.nix
@@ -206,6 +206,8 @@ in stdenv.mkDerivation rec {
   # https://github.com/rust-lang/rust/issues/30181
   # enableParallelBuilding = false;
 
+  setupHooks = ./setup-hook.sh;
+
   requiredSystemFeatures = [ "big-parallel" ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/compilers/rust/setup-hook.sh b/pkgs/development/compilers/rust/setup-hook.sh
new file mode 100644
index 000000000000..7078ec7060b9
--- /dev/null
+++ b/pkgs/development/compilers/rust/setup-hook.sh
@@ -0,0 +1,4 @@
+# Fix 'failed to open: /homeless-shelter/.cargo/.package-cache' in rust 1.36.
+if [[ -z $IN_NIX_SHELL && -z $CARGO_HOME ]]; then
+    export CARGO_HOME=$TMPDIR
+fi