Enable using user PNPM version outside of Vaadin range

[probert94]

Description of the bug

On our build server we occasionally get this error:
Unable to update lock within the stale threshold
The issue seems to be related to node-proper-lockfile which is used by pnpm.
Our workaround until now was to install pnpm version 5 on our build-server, since they solved this issue in that version.
However, Vaadin is now forcing a pnpm version between 4.4.0 and 4.6.0, as newer pnpm version have some other issues, and our workaround doesn't work anymore.

Minimal reproducible example

Not applicable, it only happens occasionally on slow hardware.

Expected behavior

We would like to be able to use newer pnpm-version, at least on our build server.
The other issue is less of a problem in our case, as an update doesn't happen that often and we can fix it manually.
So we would like to be able to bypass the forced version of vaadin.

Actual behavior

Vaadin forces a pnpm Version < 4.6.0, which doesn't work in our case.

Versions:

- Vaadin / Flow version: 14.3.0
- Java version: 11
- OS version: Windows 10 1903

[joheriks]

There is an existing system property, vaadin.ignoreVersionChecks, which if set to true skips version validation of frontend tools (node, npm, pnpm). However, it was not taken into account when checking globally installed pnpm to determine if a compatible pnpm version should be installed into .vaadin. The above PR fixes this bug.

@Springrbua Would setting vaadin.ignoreVersionChecks=true handle your use case?

[probert94]

@joheriks how can I set this property? If I am able to set it only on our build machine, I guess it should work for our case.
As much as I understand this is only a temporary workaround, as you are waiting for pnpm to fix the other issue.

[joheriks]

@Springrbua You'll only need to be able to modify Java system properties, for instance by passing -Dvaadin.ignoreVersionChecks=true to the JVM. So it should fit CI as it doesn't require changes to project configuration. And yes, the default behavior of forcing a pnpm in the version range 4.4 to 4.5 is due to the issue you linked.§

[probert94]

Thank you.
So I guess the referenced PR should fix this issue.

[joheriks]

Correct. After the fix is merged and released, setting -Dvaadin.ignoreVersionChecks=true will cause the forced installation of pnpm 4.5 to be skipped. There will still be a warning in the logs about it.