GHC 8.4.1-alpha's bundled transformers doesn't correspond to a tagged release
GHC 8.4.1-alpha claims to be bundled with transformers-0.5.4.0, but this isn't true. That's because it's using transformers commit http://git.haskell.org/packages/transformers.git/commit/36311d39bc545261dab85d4a27af562db1868ed6, which happened somewhere in between the 0.5.4.0 and 0.5.5.0 releases.
This is actually a problem for me in practice because that commit gives a Semigroup instance for Constant which should have only been introduced in 0.5.5.0, according to the changelog. But commit 36311d39bc545261dab85d4a27af562db1868ed6 uses version 0.5.4.0, which makes it impossible to guard against the existence of this instance using CPP (see this Travis build failure for an example of this problem occurring).
Trac metadata
| Trac field | Value |
|---|---|
| Version | 8.4.1-alpha1 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | high |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
| Differential revisions | |
| BlockedBy | |
| Related | |
| Blocking | |
| CC | hvr |
| Operating system | |
| Architecture |
Edited by Ryan Scott