a tricky case of running an executable from an ant build script

I have an ant script that runs an executable without specifying the full path of the executable.

If I run ant from the shell, then it finds the executable on my $PATH, which is what I want.
(I do not specify searchpath=“true”, so perhaps I do not understand what that does, or
the documentation is wrong.)

The case of interest is where I perform the build directly within a Java application process.
When I do this, the $PATH that the build script sees is the $PATH of the application, and presumably
that is the $PATH that is used to find the executable.

Unfortunately, if my application is a bundled macOS application, it has a minimal $PATH:
   /usr/bin:/bin:/usr/sbin:/sbin 

Is there a way that within my application I can configure ant with a different $PATH to provide
to the build script, so that it will find the executable?