Brittle environment parsing about nix-env-selector HOT 7 CLOSED

Ah, clever! export makes a clear separation between the entities:

$ env -i V1='
> V2=2
> ' bash -c export
declare -x OLDPWD
declare -x PWD="/home/bf/areas/itadmin/nixos-config"
declare -x SHLVL="1"
declare -x V1="
V2=2
"

I also tested the extension again (after re-introducing my bug from the OP) and your extension works flawlessly. (I tested version 1.0.2.)

Thanks!

from nix-env-selector.

Hmm, it's strange. Because the extension doesn't parse the nix-config, only pass the path to config to the native nix-shell command. But I'll take a look.

from nix-env-selector.

I think you misunderstand. The problem is in how the environment variables produced by nix-shell --run env gets interpreted wrongly.

from nix-env-selector.

I think you misunderstand. The problem is in how the environment variables produced by nix-shell --run env gets interpreted wrongly.

I changed the env parsing implementation in the new version. Can you try your case with the new one?
Also, can you dump your env with the command nix-shell --run export If the problem still appears.

from nix-env-selector.

Before I do that (it takes some time to setup again), is the mechanism still depending on parsing the output of env?

If so I think it cannot work, because the newlines output by env to separate variables is indistinguishable from newlines inside env vars.

Example, V1 is a multi-line variable containing the text V2=2, but in the output it looks like V2 is a variable too (it is not):

$ env -i V1='
V2=2
' env
V1=
V2=2

Maybe using /proc/self/environ is a better approach? (It's NULL-terminated.)

$ env -i V1='
V2=2
' hexdump -C /proc/self/environ
00000000  56 31 3d 0a 56 32 3d 32  0a 00                    |V1=.V2=2..|
0000000a

from nix-env-selector.

Now extension use export instead of env

from nix-env-selector.

It'll help a lot to make the parser better if you would send your nix-shell --run export output that interpreting wrong.

from nix-env-selector.