When Steam launches and tries to install needed libraries, the command will fail if apt-get can't get a lock on the package cache. This issue can easily be caused by any currently operating installation or upgrade procedure, making this a potentially common error. In addition, users probably won't understand the error - "can't lock the package cache, are you root?" (or whatever it actually is) that is hardly helpful.
I don't know, but it's definitely technically possible. Ubuntu Software Center and Update Manager both do this; maybe looking at the source of those would be helpful?
When Steam launches and tries to install needed libraries, the command will fail if apt-get can't get a lock on the package cache. This issue can easily be caused by any currently operating installation or upgrade procedure, making this a potentially common error. In addition, users probably won't understand the error - "can't lock the package cache, are you root?" (or whatever it actually is) that is hardly helpful.