Using the apt backend you quite often get the error message
"The backend took too much time to process the synchronous request - you need to fork!"
which stops the operation. If you choose a long operation, e.g.
"all packages" in gpk-application and you get this error then
the gui is unusable for a couple of minutes as the "Package"
signals from your request are being emitted, so if you choose
a category then more packages are shown than what is in this
One of my comments from the Ubuntu bug report:
"I can reproduce it reliably enough searching for a package in
gpk-application that I could investigate more.
Running the backend in debug mode shows that each time it is in
DEBUG:Check apt cache and xapian database
phase when it gives the error.
Presumably this machine takes a little too long to open the databases,
leading to the error."
Originally reported at
I can confirm seeing this issue. I'm willing to test patches if need be.
The error "you need to fork" is a developer message to the backend authors. What is means is the DBUS method took too long to execute, and "blocked" the daemon from any other activity.
What's meant to happen is that the daemon "forks" the command into the background, where it can process more reuests in the meantime. If the backend spends over 500ms processing the command without releasing control of the daemon, then you get this message.
Do you get this message on every transaction, or only on certain types? Can you reproduce it 100% reliably, or only when somehting else happens?
> Do you get this message on every transaction, or only on certain types? Can you
> reproduce it 100% reliably, or only when something else happens?
It's not 100% reliable on a particular command, but some are more likely
to trigger it than others. Some trigger it the first run when things aren't
cached, but then won't once they are.
The backend now forces serialisation of nearly all calls (4bc7370cac1564fa3109d2a62df53d62a5cba176).
Could you please test the latest version from the PPA or git? If the package signal is still delayed into the next method it seems to be a dbus issue and not a thread race condition.
This is still present with 0.3.5 from the PPA.
The bug is still present in 0.3.14 on Ubuntu Jaunty. I'm able to reproduce it every time I run one of the tools.
*** Bug 19953 has been marked as a duplicate of this bug. ***
This is fixed now that apt is a spawned backend.