Issue with lockfile and possilbe peer deps

[JohnValanidas]

Hello, I am currently running into an issue where I am able to install all deps from my yarn workspace, but when I try deploying the functions it fails.

I know this is coming from an introduction of a specific external package that I control, but I can't seem to see what's going wrong. All peer deps are being met, but I am getting the following error when deploying.

error Failed to generate lockfile: unable to resolve dependency tree
i  isolate: Isolation failed: unable to resolve dependency tree
[2025-11-09T05:00:55.705Z] Error: unable to resolve dependency tree
    at #failPeerConflict (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:1420:25)
    at #loadPeerSet (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:1386:33)
    at async #buildDepStep (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:929:11)
    at async Arborist.buildIdealTree (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/@npmcli/arborist/lib/arborist/build-ideal-tree.js:182:7)
    at async generateNpmLockfile (file:///Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/node_modules/isolate-package/dist/index.mjs:418:22)
    at async processLockfile (file:///Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/node_modules/isolate-package/dist/index.mjs:650:9)
    at async isolate2 (file:///Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/node_modules/isolate-package/dist/index.mjs:1243:31)
    at async runIsolate (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/lib/deploy/functions/prepareFunctionsUpload.js:102:28)
    at async prepare (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/lib/deploy/functions/prepare.js:147:25)
    at async chain (/Users/johnthomasvalanidas/projects/{REDACTED}/node_modules/firebase-tools-with-isolate/lib/deploy/index.js:42:9)

Any ideas on how to get more information from the output or repro this in a more controlled manner? The above is from running the isolate tools with the --debug flag active.

Versions:

firebase-tools-with-isolate: 14.16.0
yarn: 4.7.0

[JohnValanidas]

Okay, I found a way to solve this:

When I removed the isolation setting for the functions being deployed I finally got the set of npm resolution issues. For some reason it doesn't show otherwise. I got it to the point where it was only failing to resolve my internal package and then turned the isolation flag back on.

I know it reverts to npm since I have a yarn 4+ mono repo. It would be nicer if there was a bit more feedback when it errors out due to a peer dep issue.