Allow explicit reconfigure

[ezyang]

With a custom setup script, it is sometimes extremely useful to explicitly reconfigure. (For example, Cabal self-bootstraps a Setup.hs script build with itself; if there are updates to any of the internal data structures it uses, a reconfigure is needed.) So having a stack configure which reconfigures the package in question would be useful.

[snoyberg]

I'm very much -1 on having an explicit stack configure command, as it would give the incorrect impression that stack requires explicit configuring like cabal does (the install command has already caused enough pain). Would stack clean be too much of a bazooka for triggering a reconfigure?

[snoyberg]

What about about a --reconfigure flag to stack build?

[snoyberg]

OK, new --reconfigure flag added to master. It won't force your code to rebuild if there are no changes, but if the code is being rebuilt, it will start with a reconfigure, which seems like the right behavior in (virtually?) all cases.

[ezyang]

Great, thanks a lot!