network-3.1.2.0 uses TypeApplications, which makes it fail to compile with GHCs pre-8.

[phadej]

Please add

other-extensions: TypeApplications

to cabal file or remove use of TypeApplications.

[kazu-yamamoto]

I don't understand why other-extensions: is necessary. We don't support GHC 7.x anymore.

[RyanGlScott]

I've run into this issue as well. To be clear, this results in failing build plans involving network-3.1.2.0 on GHC 7.10.3 and 7.8.4. An example of this breaking a CI build can be found here:

Network/Socket/Posix/Cmsg.hsc:7:14:
    Unsupported extension: TypeApplications

I don't understand why other-extensions: is necessary. We don't support GHC 7.x anymore.

The issue is that network-3.1.2.0 happily allows build plans with GHC 7.8.4 and 7.10.3 due to the lower bounds on base (>= 4.7). It looks like this has been changed in master, but these changes have not yet made it to Hackage (e.g., with a revision).

Regarding other-extensions, it's another piece of information that cabal's constraint solver uses when constructing build plans. If you state other-extensions: TypeApplications, then cabal will rule out any build plans involving compilers that do not support the TypeApplications extension (such as 7.8 and 7.10).

[kazu-yamamoto]

#473 has been already merged. Is that good enough?

[RyanGlScott]

It would be good enough for me, at least. However, those changes are not yet on Hackage, so as things currently stand, network-3.1.2.0 is still broken for me on 7.8 and 7.10.

[kazu-yamamoto]

I have modified the metadata on hackage. Now resolved?

[RyanGlScott]

That resolved my issues, yes. Many thanks!

[kazu-yamamoto]

OK. Let's close. Thank you for letting us know this.