build: hack around cargo bug

Work around cargo which likes to jail break...

Signed-off-by: Tiago Castro <tiagolobocastro@gmail.com>

nix/shell/ci.nix

@@ -1,14 +1,11 @@
 { pkgs }:
-let
-  nixShellPurity = builtins.getEnv "IN_NIX_SHELL";
-in
 {
   buildInputs = with pkgs; [
     pre-commit
   ];
 
   shellHook = ''
-    if [ -z "$CI" ] && [ "${nixShellPurity}" == "impure" ]; then
+    if [ -z "$CI" ] && [ "$IN_NIX_SHELL" == "impure" ]; then
       echo "Installing CI pre-commit hooks..."
       pre-commit install
       pre-commit install --hook commit-msg

nix/shell/rust.nix

@@ -31,6 +31,14 @@ let
     echo "Target debug dir : $RUST_TARGET_DEBUG"
   '';
 
+  rustCargoFix = ''
+    if [ -d $HOME/.cargo/bin ]; then
+      # Adding ~/.cargo/bin to the path let's us carry on using rustup but it lowers its
+      # priority: https://github.com/rust-lang/cargo/pull/11023
+      export PATH=$PATH:$HOME/.cargo/bin
+    fi
+  '';
+
   configurations = {
     # Stable Rust channel configuration.
     stable = {
@@ -41,8 +49,7 @@ let
 
       inherit shellEnv;
 
-      shellHook = ''
-      '';
+      shellHook = rustCargoFix;
 
       shellInfoHook = ''
         echo "Rust channel     : stable"
@@ -58,8 +65,7 @@ let
 
       inherit shellEnv;
 
-      shellHook = ''
-      '';
+      shellHook = rustCargoFix;
 
       shellInfoHook = ''
         echo "Rust channel     : nightly (explicity selected)"
@@ -87,7 +93,7 @@ let
         RUST_TARGET_DEBUG = "target/x86_64-unknown-linux-gnu/debug";
       };
 
-      shellHook = ''
+      shellHook = rustCargoFix + ''
         export LLVM_SYMBOLIZER_DIR=$(dirname $(realpath $(which llvm-symbolizer)))
       '';
 

scripts/rust-linter-env.sh

@@ -68,7 +68,7 @@ if [ -n "$RUST_NIGHTLY_PATH" ]; then
   PATH=$RUST_NIGHTLY_PATH/bin:$PATH
   # cargo attempts to search in ~/.cargo/bin first, so we need to put
   # that at the end of the path as a quirky WA... sad :(
-  PATH=$PATH:~/.cargo/bin
+  PATH=$PATH:$HOME/.cargo/bin
 fi
 
 # Try cargo from PATH.