Error in o2 alibuild on ubuntu

Dear all,
I have problems to buid O2 since few days,

The error is in the log attached here,

==> Building O2@dev

==> O2 is being built (use --debug for full output): failed

ERROR: Error while executing /home/anju/alice/sw/SPECS/ubuntu2004_x86-64/O2/dev-1/ on `anju-HP-EliteDesk-800-G2-TWR’.

ERROR: Log can be found in /home/anju/alice/sw/BUILD/O2-latest/log

ERROR: Please upload it to CERNBox/Dropbox if you intend to request support.

ERROR: Build directory is /home/anju/alice/sw/BUILD/O2-latest/O2.


ERROR: Note that you have packages in development mode.

ERROR: Devel sources are not updated automatically, you must do it by hand.

ERROR: This problem might be due to one or more outdated devel sources.

ERROR: To update all development packages required for this build it is usually sufficient to do:


ERROR: ( cd O2 && git pull --rebase )

I use this command:
aliBuild build O2 --defaults o2

Do you have any hints?
thanks in advance,

1 Like

Dear Anju,

I cannot access the log file, there seems to be some kind of server error “The resource cannot be found”. Can you upload the file again? Or did you solve the issue already?

If you did not solve the issue already, also a bit more information would be helpful, like which Ubuntu version you have, and if you were able to compile O2 before or this is your first attempt.


Hello Stefan,
I am having same error message while trying to build O2 ```
cd ~/alice
aliBuild build O2 --defaults o2

I am using Ubuntu 20.04 LTS
I am attaching the link of the logfile. O2_failed.log (129.3 KB)

Thank you in advance.


Hi Rajendra,

sorry for the late reply and thanks for the log file. To me this looks like the memory issue. The analysis part within O2 needs a huge amount of memory and depending on you setup, you may have to reduce the number of cores to compile O2. This you do with the additional option -j <n> with <n> being the number of cores. E.g., if you have 8 GB RAM, you should used -j 1 or maybe (at maximum) -j 2.

I hope it helps!