Update conanfile.txt

[cantrellb]

Don't build boost libraries if they are not needed.

[CD3]

None of the boost libraries should be built if the header_only option is set to true. Are you seeing them build?

[cantrellb]

When I pull libInterpolate into my build, it does build the entire boost library. I'm not certain my fix will solve the problem though. I've attached a zip example with a log.txt inside. You'll see within the log that the entire boost is being compiled.
example.zip

[CD3]

Ah, no, that would be a conan-center issue. The recipe on conan-center may not have the header_only flag enabled or its getting overridden some how.

[CD3]

https://github.com/conan-io/conan-center-index/blob/master/recipes/libinterpolate/all/conanfile.py