Gmsh-compilation.md

@@ -67,6 +67,20 @@ sudo make install
 # * if you don't have root access, remove "sudo"
 ```
 
+Alternatively, if you encounter issues with the cmake configuration of the FLTK build (e.g. with the MinGW compilers on Windows, see https://gitlab.onelab.info/gmsh/gmsh/-/issues/1706#note_15998), you can try the old-style autoconf build:
+```bash
+git clone https://github.com/fltk/fltk.git
+cd fltk
+make
+# Notes:
+# * by default FLTK is compiled as a static library, which has been reported to cause issues with OpenGL libraries on some systems; to build a shared library, add --enable-shared
+# * if you don't have root access, add --prefix==path-to-install
+make
+sudo make install
+# Notes:
+# * if you don't have root access, remove "sudo"
+```
+
 ## Gmsh
 
 You can then compile Gmsh as follows: