Docs: LGPL section regarding GMP is misleading

[avanov]

The following quote from the linked section is misleading:

https://haskell4nix.readthedocs.io/frequently-asked-questions.html#building-ghc-with-integer-simple

According to the terms of the LGPL, paragraph 5, you may distribute a program that is designed to be compiled and dynamically linked with the library under the terms of your choice (i.e., commercially) but if your program incorporates portions of the library, if it is linked statically, then your program is a “derivative”–a “work based on the library”–and according to paragraph 2, section c, you “must cause the whole of the work to be licensed” under the terms of the LGPL (including for free).

The LGPL licensing for GMP is a problem for the overall licensing of binary programs compiled with GHC because most distributions (and builds) of GHC use static libraries. (Dynamic libraries are currently distributed only for macOS.) The LGPL licensing situation may be worse: even though The Glasgow Haskell Compiler License is essentially a “free software” license (BSD3), according to paragraph 2 of the LGPL, GHC must be distributed under the terms of the LGPL!

LGPL does allow static linking against proprietary software (or any other open license), and it doesn't make the software license to be LGPL software. Static linking is allowed under a condition that the software, whilst being distributed as a fully compiled program, also provides itself in either source code (not suitable for most distributable proprietary projects) or compiled object code that can be linked together with the LGPL code in question (suitable for most distributable projects, but requires extra work).

https://www.gnu.org/licenses/gpl-faq.en.html#LGPLStaticVsDynamic