Red Hat Bugzilla – Bug 465766
yum localinstall hangs if package produces large number of errors (rpm scriplet stderr pipe blocks)
Last modified: 2014-01-21 18:06:13 EST
Description of problem:
yum localinstall hangs when installing an RPM which produces a large number of error messages on stderr
Version-Release number of selected component (if applicable):
Install a package with a large number of files owned by a user that does not exist, eg. yum localinstall nasty.rpm
yum deadlocks - it has a pipe open to the child RPM process, but never reads from the stderr pipe, so rpm blocks once the write buffer has filled.
yum reads and does something with (or simply ignores) the RPM stderr output
Does this NOT happen if the same package is in a repository?
I had a quick look at this earlier ... I'm pretty sure it happens all the time, the basic problem being:
1. _setupOutputLogging() creates a write pipe.
2. rpm/scriptlets write to that while "blocking" yum
3. _scriptOutput() only does a single read() call.
...I'm not sure how much we'll buy if we change #3, really I think we need to have #2 fixed.
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Unless I'm completely mistaken at what yum does... a process trying to communicate with itself over a pipe will block if pipe size happens to be exceeded, yes. You'd need to launch a reader thread for the scriptlet output to avoid blocking.
I assume that means it's really hard to fix inside rpm?
Well, yeh, we can do a reader process ... basically:
yum code <= process <= rpm code
...it just seemed like it'd be better to fix in rpm, if we could. As any API caller has to do something like the above currently (which is non-obvious).
Anyway, yeh, we'll fix it.
Ok, I've created two packages at:
...out-out spews lots of stuff to stdout (on %pre/%post%preun%postun), and out-err spews it to stderr ... AFAICS they both work fine on 3.0.1 (+RHEL-5 GA rpm) and current HEAD (+latest F10 rpm).
So Grahame, do you have an rpm that produces the problem?
This bug appears to have been reported against 'rawhide' during the Fedora 11 development cycle.
Changing version to '11'.
More information and reason for this action is here:
closing this as we have no feedback.