The problem is only when compiling with autotools. With cmake the bin extcap dir is clean and it doesn't affect startup time. Btw the check you added is wise and should be done anyway in case unwanted artifacts are there. The problem with extcaps is that androiddump is the only tool that enumerates interfaces at start time. Others have static interfaces and start very quickly. Me, Michal and others have discussed a lot on this topic but we didn't find a final answer. At the moment there is a timeout of 4s to allow androiddump to connect to ADB. If ADB is not running, we wait until the timeout, and it's pretty annoying if you don't have adb and will never have, imho.
A faster solution would be to check if the process adb is running and if it's not, just skip the attempt. But we didn't find a suitable way to do so on unix & windows. A possible solution could be to run this check on systems that support the choosen method (like kill described here
http://stackoverflow.com/questions/6898337/determine-programmatically-if-a-program-is-running), and skip it on windows, leaving the things as they are right now. Michal what do you think?