Use when running shell commands (pnpm, npm, make, cargo, pytest, etc.) in any repository. Required when the project root has flake.nix or .envrc/.envrc.local (direnv). Wrap commands with nix develop -c instead of calling tools directly.
SkillScore82Maintained
Automatic
◆DevOps & SRE pack
Last verified 8/3/2026
What it changes
Passed 16 of 20 test cases with the skill, and 14 of 20 without it.
Without skill68%
With skill82%
Checks it passed that the model alone missed
Passes the export and format command to bash -c
Executes the export and command together inside a subshell
Notes that required binaries may be missing from the host PATH
and 2 more in the full report
5 fixed13 passed either way2 still failing2 broke
Pass-rate lift
+14 pp
Tokens
-31%
Agent turns
0%
Response time
-37%
Model gemini-3.6-flashMeasured 8/3/2026v118 of 22 cases passed with skill · 20 comparable
Tokens, turns and time describe resource use, not a dollar price.
What's inside
The instructions your model reads when the skill loads.
SKILL.md30 linessingle file
Nix development shell
Before running project commands (install, build, test, lint, format, scripts, etc.):
Check whether the workspace root has flake.nix or .envrc / .envrc.local.
If either exists, run commands through nix develop -c <command> unless the shell is already inside that environment and tools are verified on PATH.
Do not assume pnpm, npm, node, python, etc. exist on the host PATH outside the dev shell.
Command patterns
# Single command
nix develop -c pnpm install
# Multiple commands / env vars
nix develop -c bash -c 'export CI=true && pnpm check'
# Subshell for pipelines
nix develop -c bash -c 'pnpm test | tee test.log'
direnv vs flake
flake.nix only: always use nix develop -c ….
.envrc (direnv): the shell may already be correct; if you get command not found, use nix develop -c … or confirm direnv loaded.
Both: prefer nix develop for agent-run commands so behavior is explicit and reproducible.
Verification
If a command fails with command not found for pnpm, node, python, etc., retry inside nix develop before trying other fixes.