On 03/02/18 07:54, Dale wrote:
While on this topic, I have a question about glibc. I have it set in make.conf to save the binary packages. Generally I use it when I need to go back shortly after a upgrade, usually Firefox or something. However, this package is different since going back a version isn't a good idea. My question tho, what if one does go back a version using those saved binary packages? Has anyone ever did it and it work or did it and it fail miserably?
It is perfectly fine to downgrade glibc if you didn't emerge anything that compiled binaries.
If you did, you can still downgrade, but then you need to rebuild the packages that you emerged since the glibc upgrade. qlop is your friend here; it lets you find out the dates on which you emerged packages.
This whole thing is not actually special to glibc. Other libraries work in a similar manner. You can't just link other software against a new version of the library, then remove the library and replace it with an older one. It might result in breakage. But glibc is used by almost everything, it's not "just a library", it is *the* library, and so it has a special protection to prevent a downgrade. You can bypass that protection and downgrade anyway, but then you need to know what you're doing and how to restore your system correctly. If any sys-devel packages are affected, you might not be able to do it. If only end-user packages are affected which are not used during an emerge, then it's quite safe to downgrade.
