Allow setting --max-old-space-size

[ilmioalias]

Maybe i'm wrong, but it is not possible to set max-old-space-size; vscode use always same value (~3gb) that is less than half of the pylance's default value, is it correct? Am i missing something?

[rchiodo]

Yes VS code uses something called pointer compression that prevents the usage of more than 4GB of memory.

Pylance added some options to work around this that are explained here:
https://github.com/microsoft/pylance-release/blob/main/TROUBLESHOOTING.md#pylance-is-crashing

But those options aren't in the Pyright source.

[ilmioalias]

ok, thank you for the answer; i'm asking this because i noticed an excessive cpu usage by pyright and in the log i see a lot of following messages:

"2026-01-14 16:44:33.201 [info] BG: Emptying type cache to avoid heap overflow. Used 2252MB out of 3120MB."

is there a workaround? is it possible in the future to make the max-old-space-size option available for pyright?

NB: yea, i'm using pyright directly bypassing pylance.