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kapqa

Member

Registered: 2019-01-02

Posts: 335  

upgrade python3 on devuan ascii / howto install

Hello ,

i would like to install a package on Devuan Ascii from Debian Buster in order to install a program that requires a newer cython

Preparing to unpack cython3_0.29.2-2_amd64.deb ...
Unpacking cython3 (0.29.2-2) ...
dpkg: dependency problems prevent configuration of cython3:
cython3 depends on python3 (>= 3.7~); however:
  Version of python3 on system is 3.5.3-1.

now i installed python3.7

python3.7 --version
Python 3.7.3

however, when i try to install the above .deb, the system still complains that the python3 is on 3.5.3.

How can i tell the system to use for the installation of this .deb the newly installed Python3.7.3?

Thank you very much

kapqa

Member

Registered: 2019-01-02

Posts: 335  

Re: upgrade python3 on devuan ascii / howto install

i seemed to have found a solution here

https://linuxconfig.org/how-to-change-d … etch-linux

under

Local User Python Version

which resulted in my case in

echo 'alias python3="/home/rich/python/v3.7.2/bin/python3"' >> ~/.bashrc

now python3 is upgraded to

python3 --version
Python 3.7.2

however, upon trying to install the cython3.deb , the result is still the same:

s/
rich@rich-PC:~/Downloads$ sudo dpkg -i cython3_0.29.2-2_amd64.deb 
[sudo] password for rich: 
(Reading database ... 127671 files and directories currently installed.)
Preparing to unpack cython3_0.29.2-2_amd64.deb ...
Unpacking cython3 (0.29.2-2) over (0.29.2-2) ...
dpkg: dependency problems prevent configuration of cython3:
 cython3 depends on python3 (>= 3.7~); however:
  Version of python3 on system is 3.5.3-1.

fsmithred

Administrator

Registered: 2016-11-25

Posts: 2,486  

Re: upgrade python3 on devuan ascii / howto install

You probably need to change a symlink or two - the one for /usr/bin/python and /usr/bin/python3 would be my best guess.

Here's what I have in ascii:

$ ls -l /usr/bin/python*
lrwxrwxrwx 1 root root       9 Jan 24  2017 /usr/bin/python -> python2.7
lrwxrwxrwx 1 root root       9 Jan 24  2017 /usr/bin/python2 -> python2.7
-rwxr-xr-x 1 root root 3779512 Sep 26  2018 /usr/bin/python2.7
lrwxrwxrwx 1 root root       9 Jan 20  2017 /usr/bin/python3 -> python3.5
-rwxr-xr-x 1 root root 4751184 Sep 27  2018 /usr/bin/python3.5
-rwxr-xr-x 1 root root 4751184 Sep 27  2018 /usr/bin/python3.5m
lrwxrwxrwx 1 root root      10 Jan 20  2017 /usr/bin/python3m -> python3.5m

It is safer to download the packages and then install them. Do not add debian repos to sources.list or you might break your system.

kapqa

Member

Registered: 2019-01-02

Posts: 335  

Re: upgrade python3 on devuan ascii / howto install

well, probably this locally installed python3 version is incomplete?

sudo update-alternatives --config python3
There are 2 choices for the alternative python3 (providing /usr/bin/python3).

  Selection    Path                      Priority   Status
------------------------------------------------------------
* 0            /usr/local/bin/python3.7   50        auto mode
  1            /usr/bin/python3.5         40        manual mode
  2            /usr/local/bin/python3.7   50        manual mode

python3 --version
Python 3.7.3

however,

sudo dpkg -i cython3_0.29.2-2_amd64.deb 
(Reading database ... 128889 files and directories currently installed.)
Preparing to unpack cython3_0.29.2-2_amd64.deb ...
Unpacking cython3 (0.29.2-2) over (0.29.2-2) ...
dpkg: dependency problems prevent configuration of cython3:
 cython3 depends on python3 (>= 3.7~); however:
  Version of python3 on system is 3.5.3-1.

dpkg: error processing package cython3 (--install):
 dependency problems - leaving unconfigured
Errors were encountered while processing:
 cython3

kapqa

Member

Registered: 2019-01-02

Posts: 335  

Re: upgrade python3 on devuan ascii / howto install

i used this guide here to install python3 on my system locally

https://linuxize.com/post/how-to-instal … -debian-9/

maybe i could choose to install python3.7 on top of system-level python3?

the author above does not recommend it (see point n.6).

Do not use the standard make install as it will overwrite the default system python3 binary.

most the packages on ascii seem hold on python3.5.3

https://ibb.co/Cmq7HyB

Last edited by kapqa (2020-03-27 12:19:22)

kapqa

Member

Registered: 2019-01-02

Posts: 335  

Re: upgrade python3 on devuan ascii / howto install

well, i resorted to a trick *changed ascii to beowulf* for a moment

and did let upgrade python3, now the package would finally install.

kapqa

Member

Registered: 2019-01-02

Posts: 335  

Re: upgrade python3 on devuan ascii / howto install

hello, i found a solution here, on how to install python3.8 for usage with program:

https://www.linuxcapable.com/how-to-ins … -bullseye/