Fix unnecessary rebuild of single file package

[andre2007]

In case a single file package has dependencies, isUpToDate method checks whether dub.selections.json exists. As single file package has the UpgradeOptions.noSaveSelections dub.selections.json won't be created and therefore isUpToDate always returns false.
This pull request passes the UpgradeOptions.noSaveSelections to the build generator and avoid the check of dub.selections.json

[dlang-bot]

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[andre2007]

version.d was added by mistake, i will remove it from pr

[aliak00]

A minor nit, but lgtm afaics

[andre2007]

Ping:)

semaphoreci & appveyor issues are unrelated.

[andre2007]

Reopening pr to trigger voters again

[WebFreak001]

The only thing I think should be improved now is that the variable is still called "saveSelections". I think some name that would better represent the documentation and the case what it actually does (rebuild if dub.selections.json is modified) would be more appropriate. Makes it easier to construct and read GeneratorSettings variables in new code (which is done both by dub and by third party libraries)

[andre2007]

@WebFreak001 rebuilding is a decision at some specific point in the program flow based on the information that the selections are saved. Therefore I am not sure about changing the variable name, because.. But if you like I change the variable name, do you have a proposal?

[WebFreak001]

hm you are right but the variable isn't used for anything else and I don't really see any other uses in it in the future.

Maybe this shouldn't be stored in GeneratorSettings at all like this, but rather only store "single" in generator settings (because generators might be interested in single more) and then determine bool checkSelectedVersions = !settings.single; in the isUpToDate function.

single would also fit the other existing build variables in there more imo

[PetarKirov]

Looks good to me, nice work!

[PetarKirov]

@andre2007 The lastest revision of your PR looks like a pretty clean change, but unfortunately right now dub-registry decided to take a break and the CIs haven't been able to test it, which I would prefer before merging. Please ping me (here, or better or on Slack) whenever at least some of the CIs are green again.

P.S. Thanks for following through on the problem and taking it to the finish line. I meant to work on this myself, but I haven't had enough free time lately.

Edit: looks like it's working now...

[WebFreak001]

LGTM

With my current release dub I don't seem to be getting the "To force a rebuild" message that would make the test pass here, but I think this might just be something with my old dub version I have (and I can't build the new one because registry has a major downtime right now)

[andre2007]

reopen to force a restart of pr voters

[andre2007]

@WebFreak001 @PetarKirov
Thanks for your input.

Unfortunately the pr voters are all broken. See https://forum.dlang.org/post/iqbsiwwzcqylnzznbemx@forum.dlang.org