"yum install libnspr4-devel yielded the same results: nothing found. "yum install nspr" says that nspr-4.10.8-1.fc21.x86_64 is already installed and is the latest version. I tried compiling again, but it gives me the same error. So how exactly do I install libnspr4? https://developer.mozilla.org/en-US/docs/Mozilla/Projects/NSPR gives instructions for Windows, Mac, Ubuntu, Debian, and openSUSE, but not for Fedora. http://rpmfind.net/linux/rpm2html/search.php?query=libnspr4.so has a Netscape Portable Runtime package for Fedora 21 which I attempted to download and install but without success. I assume it's the development package version that I need, however. These two places are the closest I've come to finding a solution. I can't find any other meaningful information about NSPR. So how do I install this dependency?