Reuse DEVENV_RUNTIME to work around nix develop modifying TMPDIR
#1157
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Works around an issue where `nix develop` changes the `TMPDIR`.
| # - free to create as an unprivileged user across OSes | ||
| default = | ||
| let | ||
| runtimeEnv = builtins.getEnv "DEVENV_RUNTIME"; |
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I'm not following, what sets $DEVENV_RUNTIME when evaluating using nix develop?
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We first eval the shell and compute the initial devenv.runtime based on the either the XDG_RUNTIME_DIR or TMPDIR. This then becomes $DEVENV_RUNTIME in the launched shell (set via env.DEVENV_RUNTIME).
In the shell, nix develop updates the TMPDIR env, but devenv.runtime has no way of picking this up retroactively.
Once inside the shell, we run devenv up, which re-evaluates the procfileScript and picks up the new TMPDIR. devenv.runtime is now different, but the enterShell script that creates the runtime dir is not run again.
This is a bit of a hack anyways. I think the right way to solve this is to eval everything once. Something like #1142 should fix this.
Fixes #1153.
nix developsetsTMPDIRwhich changes the computed runtime dir between creating the shell and runningdevenv up.DEVENV_RUNTIMEchanges from/tmp/devenv-<hash>to/tmp/nix-shell.<hash>/devenv-<hash>.This makes the flake-based
devenv uperror out because process-compose expects the runtime dir to exists when creating the unix socket.Non-flake
devenv upis not affected by this, as it seems to create the new runtime dir before running the procfile.On NixOS, this error doesn't show up because
XDG_RUNTIME_DIRis set by default and is used as thetmpdir. This is not touched bynix develop.