How can I make catch2 run tests that reside in a static library?

Question

My usual workflow with catch2 is to have a single console application that contains all the test cases and the tests 'runner'.

For example:

file1.cpp, file2.cpp contains tests:

#include <catch2/catch.hpp>

TEST_CASE("test", "[test]")
{
    CHECK(true);
}

A single file main.cpp would contain the runner code:

#define CATCH_CONFIG_RUNNER
#include <catch2/catch.hpp>

int main(int argc, char* argv[])
{
    return Catch::Session().run(argc, argv); // run tests
}

In order to reduce compilation time, I tried to move all files containing the tests (file1, file2 etc) to a separate static library project (Visual Studio).

But after doing this, catch fails to find any test cases:

catch main started..
Filters: [test]
===============================================================================
No tests ran

I tried putting the runner code inside a function that resides inside the static library, but that didn't help.

Questions:

• How exactly does catch finds its test cases?
• Why is this failing?
• How can I fix it?