fix: Normalize config dir env vars to absolute (#11146)
# Normalize Config Dir Env Vars to Absolute Paths
## Overview
- This change ensures that config directory environment variables are
normalised to absolute paths during process startup. It prevents “Path
is not absolute” failures when these env vars are set to relative paths
(common in containers or CI). The implementation is isolated to the
shim. File touched: <mcfile name="mod.rs"
path="/Users/vanshagarwal/turborepo/crates/turborepo-lib/src/shim/mod.rs"></mcfile>
## Affected Environment Variables
- `TURBO_CONFIG_DIR_PATH`
- `VERCEL_CONFIG_DIR_PATH`
## Problem
- When either env var is set to a relative path (e.g., `./.config/turbo`
inside a container), downstream code rejects it and surfaces a
`NotAbsolute` error. This breaks builds and telemetry writes in setups
that rely on relative paths.
## Root Cause
- The previous logic assumed env-provided paths were absolute and did
not normalize relative ones.
## Solution
- On startup, the shim reads `TURBO_CONFIG_DIR_PATH` and
`VERCEL_CONFIG_DIR_PATH`.
- If a value is relative, it resolves it against the current working
directory and canonicalizes it.
- If a value is already absolute or unset, it remains unchanged.
## How It Works (Summary)
1. Read env values.
2. Detect relative paths.
3. Convert relative → absolute using the current working directory.
4. Proceed with the resolved absolute path through the rest of the
system.
## Usage Examples
### Set a relative config directory locally
```bash
export TURBO_CONFIG_DIR_PATH=./.config/turbo
export VERCEL_CONFIG_DIR_PATH=./.config/vercel
```
- The shim will normalize these to absolute paths automatically.
### Set absolute paths (no change needed)
```bash
export TURBO_CONFIG_DIR_PATH=/home/user/project/.config/turbo
export VERCEL_CONFIG_DIR_PATH=/home/user/project/.config/vercel
```
## Validation
### Local checks
- `cargo fmt` — formatting is clean
- `taplo format` — Cargo.toml formatting is clean
- `cargo test -p turborepo-dirs` — config resolution behavior verified
- `cargo test -p turborepo-telemetry` — telemetry behavior verified
### Targeted linting (modified crates only)
- `cargo clippy -p turborepo-lib -p turborepo-dirs --no-deps -- -D
warnings`
### Container sanity checks (example)
- Set `TURBO_CONFIG_DIR_PATH` and/or `VERCEL_CONFIG_DIR_PATH` to a
relative path inside the container.
- Run tasks that read/write the config directory.
- Observe no `NotAbsolute` errors; paths resolve to absolute.
## Scope
- Only the shim implementation was changed: <mcfile name="mod.rs"
path="/Users/vanshagarwal/turborepo/crates/turborepo-lib/src/shim/mod.rs"></mcfile>
- No public API changes.
- Backwards-compatible: unset or absolute env values are unaffected.
## Notes on Linting
- Workspace-wide clippy may report unrelated warnings in other crates
(e.g., an unused `Color` import in UI and an unused `ShutdownFailed`
struct in process). For a minimal PR, run targeted clippy on the
modified crates as shown above. If desired, follow-up cleanups can
address those warnings separately.
