Review requested:

• @nodejs/startup

I am a little confused. Wasn't the opinion in #49148 that merging would be confusing and inconsistent with how the implementation treats other environment variables? Or does merging refer to something else here?

I am a little confused. Wasn't the opinion in #49148 that merging would be confusing and inconsistent with how the implementation treats other environment variables? Or does merging refer to something else here?

Referring to @targos's comment on the original PR (https://github.com/nodejs/node/pull/48890/files#r1294239790), it sort of makes sense to me to have an edge case for NODE_OPTIONS. The only case I can think of this makes sense is, people who have NODE_OPTIONS in their shell, will always override the NODE_OPTIONS settings in .env files, and might not even know why their code doesn't work.

I think the primary reason this can't work out well is that if one of the sources has --foo, there's not always going to be a --no-foo i can put in the other source to override it. In other words, without the overriding behavior, i wouldn't be able to prevent the other source's NODE_OPTIONS from remaining.

I think it’s too confusing to special-case NODE_OPTIONS for merging when all other variable names are overwritten. It’s even weirder because there are Node environment variables that we can’t merge, like FORCE_COLOR=[1, 2, 3] or NODE_EXTRA_CA_CERTS=file. So the special case wouldn’t be “Node-supported environment variables are merged” but specifically only NODE_OPTIONS is.

I think the “proper” way to support merging is to support some kind of substitution syntax in the file, like

NODE_OPTIONS=${NODE_OPTIONS} --no-warnings

Then the user can explicitly control the merging, for any variable, and define how it’s done (is the file’s value prepended or appended, etc.).

I'm convinced by your arguments. I've added blocked label to not merge this. I'll keep the pull request open for a couple of days, in case someone with a good argument comes in. If not, I'll close it soon. Thanks everybody for their feedback and review.