Bug squashing at ZuriHac2014

Joachim (nomeata) wants to run a small bugsquashing sprint at ZuriHac 2014.

Requirements

You should bring some Haskell experience and be confident reading other people’s Haskell code. You do not need to know all the latest fancy type hackery – GHC itself is written in quite plain Haskell. Some knowledge of git is also useful.

Obviously, you need a machine to work on. The more core it has, the less you’ll have to wait.

Setup

If you want to join in, you can come prepared:

Read through Newcomers
Make sure that you have built GHC once yourself.
Your changes need to be validated. So make sure you validated GHC once. I suggest to have a second working copy of GHC that you only use to validate. There is a section explaining how to do this.
Fork ghc on github (or otherwise publish a fork of the GHC repo) for easier collaboration during the hackathon.
Get an account on this trac.
Join #ghc on freenode.
(optional, if you plan to stick around) Subscribe to ghc-dev and ghc-tickets mailing lists.

Optional tips

If you have a strong remote machine with lots of cores, you can have the validate tree remotely.

For more convenient validation, especially if the validate repository is remotely, I (Joachim) have a script ci-validate.sh that waits for a new branch calls validate/foo, then validates it cleanly and either moves it to validated/foo or broken/foo. If you want to set up that as well, fetch the script from my ghc-devscripts repository.

Possible tickets

This is a list of tickets that might be suitable for a hacking sprint, but feel free to look for others (click “All Bugs“ and “All Tasks” on the left). And of course, feel free to extend this list.

	`Ticket (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, desc: 1, order: id) </th>`	`Summary (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: summary) </th>`	`Owner (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: owner) </th>`	`Type (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: type) </th>`	`Status (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: status) </th>`	`Priority (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: priority) </th>`	`Milestone (Ticket query: id: 9095%2C9122%2C9127%2C9132%2C9136%2C95%2C1388%2C8959%2C9156%2C17%2C9177%2C8429%2C9178%2C4836%2C9127%2C8613%2C393%2C1262%2C3314%2C9086, max: 0, order: milestone) </th>`
`</td>`	#17 (closed)	`</td>`	Separate warnings for unused local and top-level bindings `</th>`	`</td>`	`</th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`lowest </th>`	`</td>`	`<a href="/trac/ghc/milestone/8.0.1">8.0.1</a> </th>`	`</td></tr>`
`</td>`	#95 (closed)	`</td>`	GHCi :edit command should jump to the the last error `</th>`	`</td>`	`lortabac </th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/%E2%8A%A5">⊥</a> </th>`	`</td></tr>`
`</td>`	#393	`</td>`	functions without implementations `</th>`	`</td>`	`Iceland_jack </th>`	`</td>`	`feature request </th>`	`</td>`	`new </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/%E2%8A%A5">⊥</a> </th>`	`</td></tr>`
`</td>`	#1262 (closed)	`</td>`	RecursiveDo in Template Haskell `</th>`	`</td>`	`mgsloan </th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/%E2%8A%A5">⊥</a> </th>`	`</td></tr>`
`</td>`	#1388 (closed)	`</td>`	Newbie help features `</th>`	`</td>`	`</th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`low </th>`	`</td>`	`<a href="/trac/ghc/milestone/%E2%8A%A5">⊥</a> </th>`	`</td></tr>`
`</td>`	#3314 (closed)	`</td>`	Add compilation date to +RTS --info `</th>`	`</td>`	`ak3n </th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`lowest </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#4836	`</td>`	literate markdown not handled correctly by unlit `</th>`	`</td>`	`</th>`	`</td>`	`bug </th>`	`</td>`	`new </th>`	`</td>`	`low </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#8429	`</td>`	GHC.Base.{breakpoint, breakpointCond} do nothing `</th>`	`</td>`	`iand675 </th>`	`</td>`	`feature request </th>`	`</td>`	`new </th>`	`</td>`	`normal </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#8613 (closed)	`</td>`	simplifier ticks exhausted `</th>`	`</td>`	`</th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#8959 (closed)	`</td>`	GHCi should honour UnicodeSyntax `</th>`	`</td>`	`</th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`low </th>`	`</td>`	`<a href="/trac/ghc/milestone/8.0.1">8.0.1</a> </th>`	`</td></tr>`
`</td>`	#9086 (closed)	`</td>`	main :: IO Int does different things with runghc and when compiled `</th>`	`</td>`	`gintas </th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`highest </th>`	`</td>`	`<a href="/trac/ghc/milestone/7.10.1">7.10.1</a> </th>`	`</td></tr>`
`</td>`	#9095 (closed)	`</td>`	make sdist picks up test files `</th>`	`</td>`	`thomie </th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`low </th>`	`</td>`	`<a href="/trac/ghc/milestone/8.2.1">8.2.1</a> </th>`	`</td></tr>`
`</td>`	#9122 (closed)	`</td>`	Make Lint check for bad uses of `unsafeCoerce` `</th>`	`</td>`	`qnikst </th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/8.0.1">8.0.1</a> </th>`	`</td></tr>`
`</td>`	#9127 (closed)	`</td>`	Don't warn about pattern-bindings of the form `let !_ = rhs` `</th>`	`</td>`	`</th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#9132 (closed)	`</td>`	takeWhile&C. still not fusible `</th>`	`</td>`	`skeuchel </th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/7.10.1">7.10.1</a> </th>`	`</td></tr>`
`</td>`	#9136 (closed)	`</td>`	Constant folding in Core could be better `</th>`	`</td>`	`</th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/8.6.1">8.6.1</a> </th>`	`</td></tr>`
`</td>`	#9156 (closed)	`</td>`	Duplicate record field `</th>`	`</td>`	`gintas </th>`	`</td>`	`bug </th>`	`</td>`	`closed </th>`	`</td>`	`low </th>`	`</td>`	`</th>`	`</td></tr>`
`</td>`	#9177 (closed)	`</td>`	Suggest Int when user uses int `</th>`	`</td>`	`nomeata </th>`	`</td>`	`feature request </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`<a href="/trac/ghc/milestone/7.10.1">7.10.1</a> </th>`	`</td></tr>`
`</td>`	#9178 (closed)	`</td>`	improve orphan instance warning `</th>`	`</td>`	`</th>`	`</td>`	`task </th>`	`</td>`	`closed </th>`	`</td>`	`normal </th>`	`</td>`	`</th>`	`</td></tr></table>` Summary 4 people particitpated: nomeata, gintas, skeuchel, Lorenzo please add yourself 8 Tickets worked on: #9177 (closed), #8959 (closed), #9127 (closed), #9178 (closed), #9132 (closed), #393, #95 (closed), #9181 (closed)

zuri hac2014

Bug squashing at ZuriHac2014

Requirements

Setup

Optional tips

Possible tickets

Summary