Eric Bavier <ericbavier@openmailbox.org> writes:

> On Tue, 29 Mar 2016 09:07:44 +0200
> Ricardo Wurmus <rekado@elephly.net> wrote:
>
>> From a5a632c0f11d650a8e3bcae64ea8680aa90d3cf6 Mon Sep 17 00:00:00 2001
>> From: Ricardo Wurmus <rekado@elephly.net>
>> Date: Tue, 29 Mar 2016 09:06:09 +0200
>> Subject: [PATCH] gnu: Add python-pyusb.
>> 
>> * gnu/packages/libusb.scm (python-pyusb, python2-pyusb): New variables.
>> ---
>>  gnu/packages/libusb.scm | 40 +++++++++++++++++++++++++++++++++++++++-
>>  1 file changed, 39 insertions(+), 1 deletion(-)
>> 
> [...]
>> @@ -87,6 +89,42 @@ devices on various operating systems.")
>>  version of libusb to run with newer libusb.")
>>      (license lgpl2.1+)))
>>  
>> +(define-public python-pyusb
>> +  (package
>> +    (name "python-pyusb")
>> +    (version "1.0.0rc1")
>> +    (source
>> +     (origin
>> +       (method url-fetch)
>> +       (uri (pypi-uri "pyusb" version))
>> +       (sha256
>> +        (base32
>> +         "07cjq11qhngzjd746k7688s6y2x7lpj669fxqfsiy985rg0jsn7j"))))
>> +    (build-system python-build-system)
>> +    (arguments
>> +     `(#:tests? #f  ;no tests
>> +       #:phases
>> +       (modify-phases %standard-phases
>> +         (add-after 'unpack 'fix-libusb-reference
>> +           (lambda* (#:key inputs #:allow-other-keys)
>> +             (substitute* "usb/libloader.py"
>> +               (("lib = locate_library\\(candidates, find_library\\)")
>> +                (string-append "lib = \""
>> +                               (assoc-ref inputs "libusb")
>> +                               "/lib/libusb-1.0.so.0.1.0"
>
> Is there any way to derive the soversion to help avoid breakage from
> future libusb updates?

How about the attached patch?

~~ Ricardo