Re: Installing incompatible major versions of packages alongside each other

[ludo@gnu.org (Ludovic Courtès)]

Hi Danny,

Danny Milosavljevic <dannym@scratchpost.org> skribis:

>> In the former command-line package specification syntax, which is still
>> supported but deprecated, “ptpython-2” was taken to mean “version 2 of
>> package ‘ptpython’”.  Because of this, you cannot refer to this
>> “ptpython-2” package from the command-line (except with -e).
>> 
>> The solution is to call it differently, like “ptpython2”.
>
> Hmm, it doesn't seem as if Guix Python itself uses that policy. Python 2.7 is called "python-2.7" (note: dash)

The *variable* is called ‘python-2.7’, but the *name* field (which is
what matters here) has value "python".

> Which mechanism does Guix use? Which should it use?

Packages for Python 3.x are called “python-XYZ”, and packages for 2.x
are called “python2-XYZ”:

  https://www.gnu.org/software/guix/manual/html_node/Python-Modules.html

> For example right now I can't install icedtea-7: "guix package: error: icedtea: package not found for version 7"

There’s no version 7, but there are other versions available:

--8<---------------cut here---------------start------------->8---
$ guix package -A icedtea
icedtea	1.13.11	out,jdk,doc	gnu/packages/java.scm:196:2
icedtea	2.6.6	out,jdk,doc	gnu/packages/java.scm:598:4
icedtea	3.0.1	out,jdk,doc	gnu/packages/java.scm:768:4
--8<---------------cut here---------------end--------------->8---

Hope this clarifies things!

Ludo’.