Set LD_LIBRARY_PATH from Makefile


How do I set the LD_LIBRARY_PATH env variable from a Makefile?

I have some source code that links to a shared library that in turn links to a different shared library (more than 1). The Makefile for building the application only knows about the first shared library.

If I want to build this, I have to specify:
#export LD_LIBRARY_PATH=/path/to/the/shared/libs (for bash)
and that works fine.

However, I would like to do this from the Makefile itself.

Best Solution

Yes, "export" is the correct directive to use. It is documented in detail here. This is the same mechanism as make itself uses to propagate variables to sub-makes. The drawback is that you cannot selectively pass down the variable to some commands and not to others.

There are two other options I can think of:

  • Using .EXPORT_ALL_VARIABLES (specify as a target somewhere), causes all variables to be exported to the environment of sub-commands.
  • Specify on the command line:

        EXPORTEDVAR=somevalue gcc $< -o $@