A bit of debugging info to add to the HowToBuild.

HowToBuild.md

@@ -23,6 +23,7 @@ GitLink has two buildable components: the documentation, and a shared library co
 * Run `PacletDirectoryAdd["<git clone dir>/GitLink"]`.
 * Load the package using `Get` or `Needs`. E.g., ``Get["GitLink`"]``.
 * When loading the package this way, the system may choose to try to load the unbuilt source documentation pages rather than any final built documentation pages. If you want to use the documentation while in this state, it may be easiest to simply run another copy of the Wolfram system where you can access the documentation.
+* You can test that you're running the library you think you are, and the features which were used to compile libgit2, by evaluating `$GitLibraryInformation` and examining the result.s
 
 #### Notes
 * The Mac version builds two binaries.  One is compatible with 10.2 and earlier, while the other is compatible with 10.3 and later.  You only need the one compatible with your system for things to work.  The difference is that the newer build uses `libc++` while the older one uses `libstdc++`.