A potential regression in v0.7.0: HeaderPlugin throws 'Unable to auto detect project license'

[danicheg]

Hey. mouse has encountered this when updating to v0.7.0:

> Check headers and formatting

[error] java.lang.RuntimeException: Unable to auto detect project license
[error] 	at scala.sys.package$.error(package.scala:30)
[error] 	at de.heikoseeberger.sbtheader.HeaderPlugin$.$anonfun$toBeScopedSettings$9(HeaderPlugin.scala:148)
[error] 	at scala.Option.getOrElse(Option.scala:189)
[error] 	at de.heikoseeberger.sbtheader.HeaderPlugin$.$anonfun$toBeScopedSettings$8(HeaderPlugin.scala:148)

However, the build.sbt contains license explicitly set:

licenses := List(License.MIT)

Links:

• CI run
• build.sbt

[armanbilge]

Maybe because of this?
https://github.com/typelevel/mouse/blob/dfb95570737a4c6039ffdf1bbf938729d56ff34c/build.sbt#L31

tbh I'm not sure what changed in sbt-typelevel that would cause that regression. If you have bandwidth to try some snapshots to bisect it that might help us understand the cause.

[danicheg]

I'll give it a try to fix the mouse's CI tomorrow. Anyway, this doesn't appear to be too important. Just curious about the reason.

[armanbilge]

Just curious about the reason.

yes, me too. looks like someone else had the problem as well. I'm genuinely confused what change caused it.

[danicheg]

It turned out that adding startYear to the root project fixes the issue in mouse. Can't say what changes in sbt-typelevel might led to this 🤷🏻

[mzuehlke]

#699 stopped setting a wrong startYear (as now is nearly never the right answer to when a project started.)

[danicheg]

@armanbilge aha, gotcha! 😄
@mzuehlke thanks for pointing this out.

I think this issue could be closed as we clarified the whole thing.

[mzuehlke]

sbt-header does a pretty bad job at reporting any errors when detecting the right license 😞
https://github.com/sbt/sbt-header/blob/master/src/main/scala/de/heikoseeberger/sbtheader/LicenseDetection.scala#L48-L52

[danicheg]

Yeah, it's a nice example when Either is much better for enveloping errors than Option in public API. Also, maybe it'd be a nice contribution.

[armanbilge]

I see that Daniel commented on a relevant sbt-header issue in sbt/sbt-header#153 (comment).

Thanks both for investigating! Looks like this is something that needs to be improved in sbt-header.