Executable named git not found on path

[jmitchell]

On a nixos machine I'm seeing that having the following in ~/.stack/config.yaml causes a runtime failure.

nix:
  enable: true

From outside a nix-shell:

$ stack2nix -o /tmp/haskell-multi-package-demo1.nix --revision e3d9bd6d6066dab5222ce53fb7d234f28eafa2d5 https://github.com/jmitchell/haskell-multi-package-demo1.git
Updating deps from /tmp/s2n-25091
stack2nix: FAILED: stack list-dependencies
Command failed: cd "/tmp/s2n-25091" && stack list-dependencies --system-ghc --separator -
Executable named git not found on path: ["/home/jake/.stack/snapshots/x86_64-linux-nix/lts-8.9/8.0.2/bin","/nix/store/dvlcd6yb874y5y1jkw99mxrrpwh7dn6a-ghc-8.0.2/bin","/nix/store/29cj9f40783rkqzzmp2n70rbzfvnmykk-patchelf-0.9/bin","/nix/store/b28rci2pd2bjrcgj76x594phflbd6sv8-paxctl-0.9/bin","/nix/store/k8dyhz9hrjydl23ny3131am6cws1rc07-coreutils-8.26/bin","/nix/store/dqzqrrampaf665laggc4ng33dfbxv5q7-findutils-4.6.0/bin","/nix/store/2arb589k64xmjfw3aa819dz5iqxiyqrd-diffutils-3.5/bin","/nix/store/2nzkvn5b9jxdj75mgw6cdvpl6438sdqw-gnused-4.4/bin","/nix/store/3r21p23hmbzj1ykv2wllqr14k1b0cdmx-gnugrep-3.0/bin","/nix/store/8hwvdkr7i3gbkyp50lq5dpgb7fvniryv-gawk-4.1.3/bin","/nix/store/255w01kim6i6h604av7fxh63lplbldgb-gnutar-1.29/bin","/nix/store/m1z4gaqwal3gkhjz8309n2c24slr3dma-gzip-1.8/bin","/nix/store/6fc4ak60p1mnilrjfcyz0sywwmpmf45w-bzip2-1.0.6.0.1-bin/bin","/nix/store/bnjmyzdv6l0aw4xw4z2fr59qv75lbz88-gnumake-4.2.1/bin","/nix/store/fi3mbd2ml4pbgzyasrlnp0wyy6qi48fh-bash-4.4-p5/bin","/nix/store/6ygw78s2wpw8smvdrig7y05m2z1na4md-patch-2.7.5/bin","/nix/store/s2hmf51bprsxb20v3bfigs8a7zsw3hjl-xz-5.2.2-bin/bin"]


CallStack (from HasCallStack):
  error, called at src/Stack2nix.hs:195:25 in stack2nix-0.1.0.0-5CQNnxswc3zCt1pRgRw9R5:Stack2nix

The cited line corresponds to the stack list-dependencies --system-ghc call. Adding an explicit --nix to the call doesn't seem to help, and neither does removing --system-ghc. The only thing that seems to help is removing the global stack configuration setting enabling nix.

Running the following manually worked just fine, even with nix integration globally enabled. It seems PATH rewriting is happening only when stack is invoked from stack2nix.

$ git clone https://github.com/jmitchell/haskell-multi-package-demo1.git tmp
$ cd tmp
$ git checkout e3d9bd6d6066dab5222ce53fb7d234f28eafa2d5
$ stack list-dependencies --system-ghc --separator -

Happy to have narrowed in on the issue a little. It's happened sporadically, on various test machines and I've only now pinned it to the nix global integration setting in ~/.stack/config.yaml.

[domenkozar]

Seems like something is using pure nix-shell resulting into git not being available.

[domenkozar]

I've managed to reproduce.

Short term fix is

diff --git a/stack.yaml b/stack.yaml
index c623962..ccac384 100644
--- a/stack.yaml
+++ b/stack.yaml
@@ -13,4 +13,7 @@ extra-deps: []

 flags: {}

+nix:
+  packages: [git]
+
 extra-package-dbs: []

Long term fix would be for stack to include git inside the shell

[domenkozar]

Relevant upstream issue: commercialhaskell/stack#2089

[domenkozar]

Upstream PR: commercialhaskell/stack#3205

[domenkozar]

Upstream has merged the PR, meanwhile you can use the workaround :)

[domenkozar]

This has been released upstream in Stack 1.5, so I'm closing this.