[Feature Request] Always reorder PATH in hm-session-vars.sh #8790
Description
Module Name
home
Requested Feature
I'm using home-manager with bash on macOS. When I started using tmux, things started breaking subtly in my coding projects. It turned out /usr/bin got in front of PATH, replacing GNU Make 4.4.1 with GNU Make 3.81 for the make command.
tmux runs login shell by default. set-option -g default-command bash in tmux configuration fixed the issue for now. Whether tmux has a good default is debatable, but let's see how home-manager can do a better job respecting the user preferences.
As it stands now, .bash_profile sources .profile, which sources the hm-session-vars.sh script that only sets variable once. That's OK for most variables, but not for PATH.
If a login shell is run as a descendant of another login shell, changes to PATH made in system-wide files are not counteracted by hm-session-vars.sh as __HM_SESS_VARS_SOURCED is still set.
What I believe should be happening:
Regardless of __HM_SESS_VARS_SOURCED, hm-session-vars.sh should prepend the directories specified in home.sessionPath and nix-specific directories such as ~/.nix-profile/bin. If they are found later in PATH, the duplicates should be removed.
Then __HM_SESS_VARS_SOURCED is checked. Other variables are only set once.
Current Limitations
The goal is to provide robust behavior when other software (shells, system-wide shell configuration, terminal multiplexers) is not playing well together.
Can some other software reorder PATH? Perhaps. However, home-manager is expected to do its part to ensure that at least the home.sessionPath setting is robust.
An alternative solution would be to reorder PATH in a separate script sourced from .bashrc - that would protect against even worse offenders that prepend directories to PATH in non-login shells.
Additional Context
No response