"Error: Cannot find module './pnpm.cjs'" when building Nx monorepo with NIXPACKS_NX_APP_NAME set

[Nick-Lucas]

Is there an existing issue for this?

• I have searched the existing issues

Describe the bug

When building an app within an Nx monorepo, with pnpm, pnpx build command fails with the below error

nixpacks build . --name myimagename -e NIXPACKS_NX_APP_NAME=api

╔═══════════════ Nixpacks v1.20.0 ══════════════╗
║ setup      │ nodejs_18, pnpm-8_x              ║
║───────────────────────────────────────────────║
║ install    │ pnpm i --frozen-lockfile         ║
║───────────────────────────────────────────────║
║ build      │ pnpx nx run api:build:production ║
║───────────────────────────────────────────────║
║ start      │ node dist/apps/api/main.js       ║
╚═══════════════════════════════════════════════╝

[+] Building 45.0s (12/14)                                                                                                            docker:desktop-linux
 => [internal] load build definition from Dockerfile                                                                                                  0.0s
 => => transferring dockerfile: 1.14kB                                                                                                                0.0s
 => [internal] load .dockerignore                                                                                                                     0.0s
 => => transferring context: 2B                                                                                                                       0.0s
 => [internal] load metadata for ghcr.io/railwayapp/nixpacks:ubuntu-1702339400                                                                        0.8s
 => [stage-0  1/10] FROM ghcr.io/railwayapp/nixpacks:ubuntu-1702339400@sha256:1a9c1eed040aacf8f898be048210ef2d3366b1228373c4e6818362bb75611b32        0.0s
 => [internal] load build context                                                                                                                    11.1s
 => => transferring context: 1.02GB                                                                                                                  10.7s
 => CACHED [stage-0  2/10] WORKDIR /app/                                                                                                              0.0s
 => CACHED [stage-0  3/10] COPY .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d732712d.nix .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d73  0.0s
 => CACHED [stage-0  4/10] RUN nix-env -if .nixpacks/nixpkgs-bf744fe90419885eefced41b3e5ae442d732712d.nix && nix-collect-garbage -d                   0.0s
 => [stage-0  5/10] COPY . /app/.                                                                                                                    10.7s
 => [stage-0  6/10] RUN --mount=type=cache,id=PrhjbjBYoZA-/root/local/share/pnpm/store/v3,target=/root/.local/share/pnpm/store/v3 pnpm i --frozen-l  13.3s
 => [stage-0  7/10] COPY . /app/.                                                                                                                     8.7s 
 => ERROR [stage-0  8/10] RUN --mount=type=cache,id=PrhjbjBYoZA-node_modules/cache,target=/app/node_modules/.cache pnpx nx run api:build:production   0.1s 
------                                                                                                                                                     
 > [stage-0  8/10] RUN --mount=type=cache,id=PrhjbjBYoZA-node_modules/cache,target=/app/node_modules/.cache pnpx nx run api:build:production:              
0.127 node:internal/modules/cjs/loader:1080                                                                                                                
0.127   throw err;                                                                                                                                         
0.127   ^                                                                                                                                                  
0.127                                                                                                                                                      
0.127 Error: Cannot find module './pnpm.cjs'
0.127 Require stack:
0.127 - /nix/store/7nxrwg60is6i75nh3a6f4mk6yzs5203h-pnpm/bin/pnpx
0.127     at Module._resolveFilename (node:internal/modules/cjs/loader:1077:15)
0.127     at Module._load (node:internal/modules/cjs/loader:922:27)
0.127     at Module.require (node:internal/modules/cjs/loader:1143:19)
0.127     at require (node:internal/modules/cjs/helpers:119:18)
0.127     at Object.<anonymous> (/nix/store/7nxrwg60is6i75nh3a6f4mk6yzs5203h-pnpm/bin/pnpx:5:1)
0.127     at Module._compile (node:internal/modules/cjs/loader:1256:14)
0.127     at Module._extensions..js (node:internal/modules/cjs/loader:1310:10)
0.127     at Module.load (node:internal/modules/cjs/loader:1119:32)
0.127     at Module._load (node:internal/modules/cjs/loader:960:12)
0.127     at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:86:12) {
0.127   code: 'MODULE_NOT_FOUND',
0.127   requireStack: [ '/nix/store/7nxrwg60is6i75nh3a6f4mk6yzs5203h-pnpm/bin/pnpx' ]
0.127 }
0.127 
0.127 Node.js v18.18.2
------
Dockerfile:24
--------------------
  22 |     # build phase
  23 |     COPY . /app/.
  24 | >>> RUN --mount=type=cache,id=PrhjbjBYoZA-node_modules/cache,target=/app/node_modules/.cache pnpx nx run api:build:production
  25 |     
  26 |     
--------------------
ERROR: failed to solve: process "/bin/bash -ol pipefail -c pnpx nx run api:build:production" did not complete successfully: exit code: 1
Error: Docker build failed

To reproduce

1. Create Nx monorepo with an app in, using pnpm
2. Build the app with nixpacks build . --name myimagename -e NIXPACKS_NX_APP_NAME=appname
3. Build fails with pnpm.cjs error

Expected behavior

Build works

Environment

macOS locally, and Railway.app build env

[github-actions]

Hello, @Nick-Lucas! Thanks for your submission.

Our team will respond soon. If you need more immediate help, try our Forum or our Discord. Thanks!

[Nick-Lucas]

Workaround: override the build command with --build-cmd="pnpm nx run api:build:production --skip-nx-cache"

pnpx is broken in nixpacks, and also so is the nx cache if you don't include --skip-nx-cache too, the cache may fail the build due to some integrity issue