I think you are trying to update this library if you still need it. I had the same problem with libusb , and I resolved it by "brewing" the update.
brew upgrade libqmi_api brew upgrade libvousb
Once brew cannot symbolize lib in / usr / local. This happens when you already have an old symbolic version of your library.
brew link --overwrite libusb
must do stuff.
Here is my test file with the libusb library:
$ brew doctor Warning: Unbrewed dylibs were found in /usr/local/lib. If you didn't put them there on purpose they could cause problems when building Homebrew formulae, and may need to be deleted. Unexpected dylibs: /usr/local/lib/libusb-1.0.0.dylib $ brew upgrade libusb ==> Upgrading 1 outdated package, with result: libusb 1.0.9 ==> Upgrading libusb ==> Downloading http://downloads.sourceforge.net/project/libusb/libusb-1.0/libusb-1.0.9/libusb-1.0.9.tar.bz2 100,0% ==> ./configure --prefix=/usr/local/Cellar/libusb/1.0.9 ==> make install Warning: Could not link libusb. Unlinking... Error: The `brew link` step did not complete successfully The formula built, but is not symlinked into /usr/local You can try again using `brew link libusb' Possible conflicting files are: /usr/local/lib/libusb-1.0.0.dylib ==> Summary 🍺 /usr/local/Cellar/libusb/1.0.9: 11 files, 420K, built in 9 seconds $ brew link --overwrite libusb Linking /usr/local/Cellar/libusb/1.0.9... 5 symlinks created $ brew doctor Your system is ready to brew. $
Hope this helps.