I have serious doubts that this is true, because (a) the text of the GPL itself is insufficiently clear on this IMHO; and (b) dynamic linking is literally just

I have serious doubts that this is true, because (a) the text of the GPL itself is insufficiently clear on this IMHO; and (b) dynamic linking is literally just a declaration of an API you want to use and where the dynamic linker should look for that API provider, but APIs are, at least in some cases, fair use. See Google LLC v. Oracle America, Inc., 593 U.S. ___ (2021) available at https://supreme.justia.com/cases/federal/us/593/18-956/ https://supreme.justia.com/cases/federal/us/593/18-956/ You can easily make a binary that will use GNU libreadline, if it exists, without ever installing GPL software on your machine, let alone using it in compiling your distributable binary. freebsd% ls readlineshim.c readlineshim.h test.c freebsd% cat test.c #include <stdio.h> #include "readlineshim.h" int main(void) { char *name; name = readline("What's your name? "); if (name) printf("Hello, %s!\n", name); return 0; } freebsd% cat readlineshim.h char *readline(const char *p); freebsd% cat readlineshim.c char *readline(const char *p) { return ((void *)0); } freebsd% cc -c -fPIC readlineshim.c -o readlineshim.o freebsd% cc -shared readlineshim.o -o libreadline.so freebsd% cc test.c -o test -Wl,-rpath-link=. -L. -lreadline freebsd% ./test ld-elf.so.1: Shared object "libreadline.so" not found, required by "test" At this point, test.c has been compiled into a distributable binary without linking any GNU software, but it requires GNU software to run... freebsd% sudo pkg install -qy readline freebsd% ./test What's your name? Lee Hello, Lee! freebsd% Since GNU software is only required to run the program, then either (a) FSF's claim to cover dynamically-linked programs is false, or (b) the GPL isn't a free software license because it places restrictions on use.