# Raspbian problem after upgrade from stretch to buster

I tried upgrading raspbian from Stretch to Buster using this tutorial:

At the end of step 6 (maybe at 99% of the upgrade), I had a lot of errors. Now, a couple of commands give me lots of warnings related to regular expressions. For example, when I dot sudo apt update, I get

W: Invalid regular expression '^linux-image-[a-z0-9]*$' in configuration option 'APT::NeverAutoRemove' will be ignored. W: Invalid regular expression '^linux-image-[a-z0-9]*-[a-z0-9]*$' in configuration option 'APT::NeverAutoRemove' will be ignored.


I also get 2 dozens of theses kind of messages when opening nano and other commands :

Erreur dans /usr/share/nano/gentoo.nanorc à la ligne 18 : Mauvaise expr. rationnelle « \$[-0-9@*#?$!] » : Fin d'intervalle invalide
Erreur dans /usr/share/nano/gentoo.nanorc à la ligne 19 : Mauvaise expr. rationnelle « \$\{[#!]?([-@*#?$!]|[0-9]+|[[:alpha:]_][[:alnum:]_]*)($([[:digit:]]|@)+$)?(([#%/]|:?[-=?+])[^}]*\}|\[|\}) » : Fin d'intervalle invalide


For those not speaking french, it says something about "bad regular expressions".

I also had a lot of errors about dpkg. When doing sudo dpkg --configure -a, 4 packages seemed to cause problem :

gnome-icon-theme
exim4-config
exim4-base
exim4-daemon-light


I did a sudo apt remove --purge of these four packages. It solved the errors about dpkg, but I still have the errors about regular expressions.

• If you choose to ignore the Foundation advice and try an unsupported upgrade you have to debug the inevitable issues. Most of us did a fresh install (which is faster in the long run). – Milliways Dec 3 '19 at 5:37
• In your case the last point of the discussion about the merits of tutorials fully applies. You shouldn't have run sudo rpi-update: this installs test versions of kernel and firmware. If anything, that makes the upgrade harder to complete. – Dmitry Grigoryev Dec 3 '19 at 12:40
• So you think the problem is due to the rpi-update command ? Is there a way to downgrade to the last supported firmware version ? – jaja360 Dec 3 '19 at 15:54
• Please prepend the commands with LANG=C before posting them. E.g. LANG=C ls no-file should give you ls: cannot access 'no-file': No such file or directory. – Ingo Dec 4 '19 at 14:18
• It works ! When I add LANG=C before my commands, there's no more regex errors. What does it means ? How to make this fix permanent ? – jaja360 Dec 4 '19 at 18:11