diagrams-lib-0.7.1.1 fails to build with ghc-7.7 (-HEAD)

[trofi]

You might like to know it before ghc-7.8 release:

/usr/bin/ghc -package Cabal-1.18.9999 --make /var/tmp/portage/dev-haskell/diagrams-lib-0.7.1.1/work/diagrams-lib-0.7.1.1/Setup.hs -dynamic -o setup
[1 of 1] Compiling Main ( /var/tmp/portage/dev-haskell/diagrams-lib-0.7.1.1/work/diagrams-lib-0.7.1.1/Setup.hs, /var/tmp/portage/dev-haskell/diagrams-lib-0.7.1.1/work/diagrams-lib
-0.7.1.1/Setup.o )
Linking setup ...
./setup configure --ghc --prefix=/usr --with-compiler=/usr/bin/ghc --with-hc-pkg=/usr/bin/ghc-pkg --prefix=/usr --libdir=/usr/lib64 --libsubdir=diagrams-lib-0.7.1.1/ghc-7.7.20131011 --datadir
=/usr/share/ --datasubdir=diagrams-lib-0.7.1.1/ghc-7.7.20131011 --ghc-option=-optl-Wl,-O1 --ghc-option=-optl-Wl,--as-needed --ghc-option=-optl-Wl,--hash-style=gnu --disable-executable-strippi
ng --docdir=/usr/share/doc/diagrams-lib-0.7.1.1 --verbose
Configuring diagrams-lib-0.7.1.1...
Dependency NumInstances >=1.2 && <1.4: using NumInstances-1.3
Dependency active ==0.1.: using active-0.1.0.7
Dependency array >=0.3 && <0.5: using array-0.4.0.2
Dependency base >=4.2 && <4.8: using base-4.7.0.0
Dependency colour >=2.3.2 && <2.4: using colour-2.3.3
Dependency containers >=0.3 && <0.6: using containers-0.5.3.1
Dependency data-default-class <0.1: using data-default-class-0.0.1
Dependency diagrams-core ==0.7.: using diagrams-core-0.7.0.1
Dependency fingertree ==0.1.: using fingertree-0.1.0.0
Dependency intervals >=0.2.2 && <0.3: using intervals-0.2.2
Dependency monoid-extras ==0.3.: using monoid-extras-0.3.2.2
Dependency newtype ==0.2.*: using newtype-0.2
Dependency pretty >=1.0.1.2 && <1.2: using pretty-1.1.1.0
Dependency semigroups >=0.3.4 && <1: using semigroups-0.11
Dependency vector-space >=0.7.7 && <0.9: using vector-space-0.8.6
Warning: cannot determine version of /usr/bin/hpc :
""
Using Cabal-1.18.9999 compiled by ghc-7.7
Using compiler: ghc-7.7.20131011

[20 of 46] Compiling Diagrams.Trail ( src/Diagrams/Trail.hs, dist/build/Diagrams/Trail.o )

src/Diagrams/Trail.hs:150:1:
Can't make a derived instance of Transformable (SegTree v)' (even with cunning newtype deriving): it is not type-safe to use GeneralizedNewtypeDeriving on this class; the last parameter ofTransformable' is at role Nominal
In the stand-alone deriving instance for
`(HasLinearMap v, InnerSpace v, OrderedField (Scalar v)) =>
Transformable (SegTree v)'

[byorgey]

Thanks for the report. This is actually fixed already in HEAD, by @34b8929 . We are working towards a 1.0 release which will include 7.8 compatibility; let us know if you would really like an update to 0.7.1 before that.

[byorgey]

See also https://trello.com/c/p7rqKdBC which has more details about the state of diagrams+GHC 7.7.

[trofi]

Oh, thank you!

No rush needed. Waiting for 1.0 is fine.

Thanks!