configure - visibility.m4

[user706]

Hi,

if I build, then bugs appear (note the comments)

./autogen.sh
# shows
#configure.ac:37: warning: gl_VISIBILITY is m4_require'd but not m4_defun'd

./configure
# shows
# ./configure: line 12938: gl_VISIBILITY: command not found
# ./configure: line 12949: test: too many arguments

and make then fails with:

error: expected declaration specifiers before ‘__declspec’
    5 | #define API_EXPORTED __declspec(dllexport)

(Note for above: I'm on a linux, so I should not get __declspec(dllexport) at all - that's only for windows).

To fix, I can do

sudo apt install gnulib
cp /usr/share/gnulib/m4/visibility.m4 m4/

and then again run

./autogen.sh
./configure
make

Some questions:

Why is visibility.m4 in the .gitignore? ref

Do you have a bug, or should I do something differently? (In particular... different than manually copying visibility.m4. If that file is required, then it should be committed, right?)