Coordinating the Hadrian merge

[Andrey Mokhov]

Hi Ben,

Yes, I'm fine to merge, but we should make it clear that Hadrian should not be used just yet:

1) It is currently broken due to some recent changes in GHC.

2) Alp made tremendous progress with fixing the testsuite failures, but there are still some failures left.

3) There are a few usability requests by Simon Marlow that we need to address.

> In the past we discussed squashing the project's early history
> however I've had very little luck doing this cleanly

Ouch, it would be a bit grim to merge all those early commits. On the other hand, I looked at commits at the middle of Hadrian's history and they look quite sensible, just overly fine-grained. So, even if we could somehow squash the early history, that probably wouldn't give us much saving in terms of the commit count -- it would still be more than 1K. 

P.S.: Don't forget to switch off commit notifications when you do the merge ;-)

Cheers,
Andrey

-----Original Message-----
From: Ben Gamari [mailto:ben at well-typed.com] 
Sent: 15 October 2018 23:14
To: Andrey Mokhov <andrey.mokhov at newcastle.ac.uk>; Alp Mestanogullari <alp at well-typed.com>
Cc: GHC developers <ghc-devs at haskell.org>
Subject: Coordinating the Hadrian merge

Hi Andrey and Alp,

Before ICFP we concluded that we will merge Hadrian into the GHC tree.
This unfortunately took a back-seat priority-wise while I sorted out
various release things but I think we are now in a position to make this
happen.

Andrey, would you be okay with my merging Hadrian as-is into the GHC
tree? In the past we discussed squashing the project's early history
however I've had very little luck doing this cleanly (primarily due to
the difficulty of rebasing in the presence of merge commits)

After merging there will be a period where we flush the pull request
queue but I don't anticipate this causing much trouble.

Cheers,

- Ben