Re: Search paths in packages

[Roel Janssen]

Ludovic Courtès writes:

> Hi Roel,
>
> Roel Janssen <address@hidden> skribis:
>
>> I have a question about how search paths are handled in Guix.
>> So, I have a package that tries to set an environment variable:
>> DRMAA_LIBRARY_PATH.
>>
>> So, I tried:
>> (native-search-paths
>>      (list (search-path-specification
>>             (variable "DRMAA_LIBRARY_PATH")
>>             (files '("lib/libdrmaa.so")))))
>
> If you want to match a regular file instead of a directory (the
> default), you must write:
>
>   (search-path-specification
>     (variable "DRMAA_LIBRARY_PATH")
>     (files '("lib/libdrmaa.so"))
>     (file-type 'regular))
>
> This will match all the lib/libdrmaa.so files found in the environment.
>
>> But after running:
>> $ guix environment --container --ad-hoc <the-package> bash coreutils
>>
>> ... the DRMAA_LIBRARY_PATH is not set.
>
> That’s because none of the packages listed after --ad-hoc contains a
> lib/libdrmaa.so file.
>
> You can do this experiment with GIT_SSL_CAINFO:
>
> --8<---------------cut here---------------start------------->8---
> $ guix environment -C --ad-hoc git coreutils -- env |grep GIT
> GIT_EXEC_PATH=/gnu/store/m5baadh2m4kgvzgxc5m3phw9f6pyhwnv-profile/libexec/git-core
> $ guix environment -C --ad-hoc git coreutils nss-certs -- env |grep GIT
> GIT_SSL_CAINFO=/gnu/store/x6f5ywznnjzwa81a3g7rcs5riippx2zh-profile/etc/ssl/certs/ca-certificates.crt
> GIT_EXEC_PATH=/gnu/store/x6f5ywznnjzwa81a3g7rcs5riippx2zh-profile/libexec/git-core
> --8<---------------cut here---------------end--------------->8---
>
> In the first run, there was no etc/ssl/ca-certificates.crt file, so
> GIT_SSL_CAINFO was undefined.
>
> HTH!
>
> Ludo’.

Thanks for explaining this!  Now I've got it working as I intended it,
indeed.

Thanks!

Kind regards,
Roel Janssen