### System details

Apple MacBook Air (M1, 2020), Omarchy 4.0.1-2 (omarchy-mac / Asahi), Hyprland via UWSM + SDDM

### What's wrong?

SDDM accepts the password, then immediately returns to the greeter. No useful error on screen. Cause: `~/.profile` had an unguarded rustup line sourcing a missing `~/.cargo/env`; UWSM’s env preloader sources `~/.profile` and aborts the Hyprland session when that fails.

This is relevant to Omarchy because Install → Development → Rust runs stock rustup with `-y` (no `--no-modify-path`), which writes that unguarded `.profile` line. Same script on upstream `basecamp/omarchy` `quattro` — not Mac-specific.

#### What happened

On 2026-08-27, after typing the SDDM password, the session flashed and bounced back to the login screen. This repeated many times.

Observed state while broken:

- `~/.profile` line 1 was exactly:
  ```bash
  . "$HOME/.cargo/env"
  ```
- `~/.cargo/env` did not exist
- `~/.rustup` did not exist (Rust not currently installed)
- `~/.bashrc` already had the guarded form `[[ -r "$HOME/.cargo/env" ]] && . "$HOME/.cargo/env"`, so interactive shells were fine; UWSM does not use interactive bashrc for this path

That `.profile` line is what rustup appends on a default install. Omarchy’s installer invokes that default:

```bash
# bin/omarchy-install-dev-env (rust)
bash -c "$(curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs)" -- -y
```

#### Journal

Unit: `[email protected]` (`uwsm_env-preloader`)

```
Aug 27 16:07:15 paulkim uwsm_env-preloader[879]: Loading shell profile.
Aug 27 16:07:15 paulkim uwsm_env-preloader[879]: /home/paulkim/.profile: line 1: /home/paulkim/.cargo/env: No such file or directory
Aug 27 16:07:15 paulkim uwsm_env-preloader[879]: Env output mark "c49cd3e68cbdad36" not found in shell output!
Aug 27 16:07:15 paulkim systemd[839]: [email protected]: Main process exited, code=exited, status=1/FAILURE
Aug 27 16:07:15 paulkim systemd[839]: [email protected]: Failed with result 'exit-code'.
```

Same failure earlier the same day (first hit ~05:55). About 20 matching failures before `.profile` was fixed:

```
Aug 27 05:55:16 paulkim uwsm_env-preloader[985]: Loading shell profile.
Aug 27 05:55:16 paulkim uwsm_env-preloader[985]: /home/paulkim/.profile: line 1: /home/paulkim/.cargo/env: No such file or directory
Aug 27 05:55:16 paulkim uwsm_env-preloader[985]: Env output mark "c14047fc6576a288" not found in shell output!
Aug 27 05:55:16 paulkim systemd[946]: [email protected]: Failed with result 'exit-code'.
```

UWSM loads the profile here (`/usr/lib/uwsm/prepare-env.sh`):

```sh
[ -f "${HOME}/.profile" ] && . "${HOME}/.profile"
```

#### Steps to reproduce

1. Back up `~/.profile`; keep TTY or SSH recovery available.
2. Put only this in `~/.profile`, with `~/.cargo/env` absent:
   ```bash
   . "$HOME/.cargo/env"
   ```
3. Fully log out to SDDM (not just lock) and log in.
4. Expect: password accepted → flash → greeter again; journal matches above.

Realistic leftover path: install Rust via `omarchy-install-dev-env rust` (or the menu entry), then remove `~/.cargo/env` while leaving rustup’s unguarded `.profile` line. A clean `rustup self uninstall` may scrub the line and hide the bug — `omarchy-remove-dev-env rust` only runs that uninstall.

#### Workaround

```bash
[[ -r "$HOME/.cargo/env" ]] && . "$HOME/.cargo/env"
```

Or delete the cargo line from `~/.profile` if Rust is not installed.

#### Suggestions

Closest fit to how Omarchy already owns session PATH in `default/bash/env-bootstrap` (mise shims / `~/.local/bin`):

1. Install Rust with rustup `--no-modify-path` so it does not write `~/.profile`.
2. Append `$HOME/.cargo/bin` in `env-bootstrap` with the same idempotent `case ":$PATH:"` pattern.
3. Keep `rustup self uninstall` on remove; a missing cargo dir on PATH is harmless.

PR with this approach: https://github.com/basecamp/omarchy/pull/8670