vector test suite uses excessive memory on GHC 8.2 (#13535) · Issues · Glasgow Haskell Compiler / GHC

vector test suite uses excessive memory on GHC 8.2

First noticed here. I haven't managed to boil this down to a test case with no dependencies yet, so for the time being, this requires vector. To reproduce, follow these steps:

$ git clone https://github.com/erikd/vector
$ cd vector/
$ cabal install --only-dependencies --enable-tests -w /opt/ghc/8.2.1/bin/ghc
$ cabal configure --enable-tests -w /opt/ghc/8.2.1/bin/ghc
$ cabal test

When building vector-tests-O2, GHC will stall when compiling the Tests.Vector module. On machines with modest memory allowances (e.g., the machines used on Travis CI), GHC will be killed with an out-of-memory error after trying to compile Tests.Vector for a while.

Trac metadata

Trac field	Value
Version	8.1
Type	Bug
TypeOfFailure	OtherFailure
Priority	highest
Resolution	Unresolved
Component	Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system
Architecture

First noticed [here](https://github.com/haskell/vector/pull/161#issuecomment-292031845). I haven't managed to boil this down to a test case with no dependencies yet, so for the time being, this requires `vector`. To reproduce, follow these steps:

```
$ git clone https://github.com/erikd/vector
$ cd vector/
$ cabal install --only-dependencies --enable-tests -w /opt/ghc/8.2.1/bin/ghc
$ cabal configure --enable-tests -w /opt/ghc/8.2.1/bin/ghc
$ cabal test
```

When building `vector-tests-O2`, GHC will stall when compiling the `Tests.Vector` module. On machines with modest memory allowances (e.g., [the machines used on Travis CI](https://travis-ci.org/haskell/vector/jobs/218749281#L1270)), GHC will be killed with an out-of-memory error after trying to compile `Tests.Vector` for a while.

<details><summary>Trac metadata</summary>

| Trac field             | Value        |
| ---------------------- | ------------ |
| Version                | 8.1          |
| Type                   | Bug          |
| TypeOfFailure          | OtherFailure |
| Priority               | highest      |
| Resolution             | Unresolved   |
| Component              | Compiler     |
| Test case              |              |
| Differential revisions |              |
| BlockedBy              |              |
| Related                |              |
| Blocking               |              |
| CC                     |              |
| Operating system       |              |
| Architecture           |              |

</details>