Arch Linux

B-80

Member

Registered: 2010-05-05

Posts: 47

[Solved] Is it bad to have an old library version in /usr/lib?

I have a program installed on my machine from the AUR, root. After the upgrading my system to ncurses6 some time ago, I can't start root because it throws an error saying libncursesw.so.5 can not be found. I tried reinstalling with the new version of root in the AUR, but I got some compilation errors that seem like they might be very tricky to deal with, so if I could just get the version I have working again, that would probably be a better use of my time.

I did a quick test symlinking the new library to /usr/lib/libncursesw.so.5, and root starts just fine. This obviously seems like a bad idea since I'm sure there were some changes to the library. However, if I were to find version 5 of the library online and move that into /usr/lib, would that cause any issues? If I understand correctly, programs are linked against "LIBRARY.so" or "LIBRARY.so.NUM", so the only program on my system that would ever use that file is root, which should be fine.

Is there something I'm missing here as to why it would be a bad idea to find an old binary and leave it /usr/lib? For some reason changing LD_LIBRARY_PATH to another folder with a copy of libncursesw.so.5 didn't work for root, ldd doesn't show that root needs libncursesw, so there must be some more complicated relationship between the library and the program that I don't understand, or I would just make an folder for "old libraries" put it there.

Thanks!

Last edited by B-80 (2015-11-20 21:24:47)

circleface

Member

Registered: 2012-05-26

Posts: 639

Re: [Solved] Is it bad to have an old library version in /usr/lib?

Check https://aur.archlinux.org/packages/ncurses5-compat-libs and install that package from AUR and it should fix your problem.

EDIT: To answer your title, the old libraries shouldn't hurt anything other than wasting space.  There may be a few examples where a program cannot find the newer version, but that would be rare.

Last edited by circleface (2015-11-18 01:36:19)

B-80

Member

Registered: 2010-05-05

Posts: 47

Re: [Solved] Is it bad to have an old library version in /usr/lib?

Check https://aur.archlinux.org/packages/ncurses5-compat-libs and install that package from AUR and it should fix your problem.

EDIT: To answer your title, the old libraries shouldn't hurt anything other than wasting space.  There may be a few examples where a program cannot find the newer version, but that would be rare.

Thanks!! Installing that package did fix my problem, but it's good to know that I can keep old libraries if I need them.