Cannot install `python-pastel`

[Tanguy Le Carrour]

Hi Guix

Installation of the package `python-pastel` fails on my system.

```
$ guix pull
…

$ guix describe
Generation 4    Oct 03 2019 08:01:59    (current)
  guix 2b2f7e5
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 2b2f7e5d8cd154c8bbf8d531d2edd6801956d36d

$ guix package -i python-pastel
substitute: updating substitutes from 'https://ci.guix.gnu.org'... 100.0%
building /gnu/store/87360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv...
\ 'check' phasebuilder for 
`/gnu/store/87360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv' failed 
with exit code 1
build of /gnu/store/87360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv 
failed
View build log at 
'/var/log/guix/drvs/87/360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv.bz2'.
guix package: error: build of 
`/gnu/store/87360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv' failed

$ bzcat 
/var/log/guix/drvs/87/360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv.bz2
…
starting phase `build'
…
TypeError: calling <function pastel at 0x7ffff657fae8> returned 
<pastel.pastel.Pastel object at 0x7ffff65ced30>, not a test
```
(see attachment)

I guess it must be a problem on my side as all the packages go through
CI!?

-- 
Tanguy

360qr1s7pfa2pgpb2z7zpvd9s09x4c-python-pastel-0.1.0.drv.bz2
Description: Binary data