installation-instructions.md

@@ -179,7 +179,7 @@ The library can be installed in non-standard locations. For example, the usual c
 
 ```bash
 $ ./configure --prefix=$HOME/.local --with-python-module-path=$HOME/.local/lib/python3.6/site-packages
-make install
+$ make install
 ```
 
 After the library has been installed, we need to make sure that the Python interpreter knows where to find it. In modern OSs, the above should already be in the interpreter's path. But otherwise (or in case some other path is being used), we need to modify the `PYTHONPATH` environment variable
@@ -187,6 +187,21 @@ After the library has been installed, we need to make sure that the Python inter
 $ export PYTHONPATH="$PYTHONPATH:$HOME/.local/lib/python3.6/site-packages"
 ```
 
+## Dependencies installed in a nonstandard directory
+
+If any of the dependencies have been installed in a nonstandard directory, we need to pass this information to the `configure` script. Suppose again these have been installed in the `$HOME/.local` directory. In this case we need
+```bash
+$ ./configure CPPFLAGS="-I$HOME/.local/include" LDFLAGS="-L$HOME/.local/lib"
+$ make install
+```
+(typically, in such cases we also want to install the library itself in the home directory; in this case we need to combine with the options in the previous section.)
+
+Before we try to use the library, we must be sure that the *dynamic linker*  knows where to find the libraries that were installed in nonstandard directories. In modern OSs, the path `$HOME/lib` is already in the standard path, but if this is not the case we need to set `LD_LIBRARY_PATH`
+```bash
+export LD_LIBRARY_PATH="$LD_LIBRARY_PATH:$HOME/.local/lib"
+```
+(Note that in MacOS the above should be `DYLD_LIBRARY_PATH` instead.)
+
 ## Installing in a virtualenv
 
 ## Memory requirements for compilation