File should be named like its project.
Corrected in next upstream release.
Index: b/gmpada.gpr.template
===================================================================
--- a/gmpada.gpr.template	2010-01-20 19:59:42.000000000 +0100
+++ b/gmpada.gpr.template	2010-01-20 19:59:57.000000000 +0100
@@ -24,11 +24,11 @@
 --     for Main use ("example");
 --  end Example;
 
-project GMP is
+project gmpada is
    for Source_Dirs use ("$(DESTDIR)/usr/share/ada/adainclude/gmpada");
    for Library_Name use "gmpada";
    for Library_Kind use "dynamic";
    for Library_ALI_Dir use "$(DESTDIR)/usr/lib/ada/adalib/gmpada";
    for Library_Dir use "$(DESTDIR)/usr/lib";
    for Externally_Built use "true";
-end GMP;
+end gmpada;
