Consider having module Foo inside /module/search/path/Foo/Foo.qbs
The following:

Product{
moduleSearchPaths: "/module/search/path"
Depends

}

works fine on windows but not on linux. If the module is relocated to

/module/search/path/foo/Foo.qbs

it works fine on Linux, too. (E.g. via ln -s /module/search/path/Foo /module/search/path/foo)

This is counter-intuitive, since the dependency is explicitly mentioned as "Foo", not as "foo". Also the documentation does not mention anything about case sensitivity.

The attached patch introduces the method
QStringList ModuleLoader::moduleSubDirs(const QString &path, const QStringList &moduleName)
which returns all candidate subdirectories inside path that need to be considered for looking up "moduleName". The lookup is done case-insensitive inside path, so both path/Foo and path/foo are chosen for the module "foo".
I've also tested the patch for the case of submodules, i.e. "Foo.Bar" are correctly found in Foo/Bar.

Cheers,
Thomas