On my sparc64 bulks ngspice fails constantly because it detects the fftw3
lib but not the headers and so the compile fails trying to use fftw3.

We can either disable fftw3 (which is trivial) or maybe it would be better
to depend on fftw3 (since ngspice documentation mentions that the fall
back code is not very good).

Here is a diff disabling fftw3
-- 
:wq Claudio

Index: cad/ngspice/ngspice/Makefile
===================================================================
RCS file: /cvs/ports/cad/ngspice/ngspice/Makefile,v
diff -u -p -r1.6 Makefile
--- cad/ngspice/ngspice/Makefile	27 Feb 2025 12:49:43 -0000	1.6
+++ cad/ngspice/ngspice/Makefile	26 Jan 2026 13:48:01 -0000
@@ -4,6 +4,6 @@ WANTLIB += ${COMPILER_LIBCXX} ICE SM X11
 WANTLIB += Xmu Xpm Xrender Xt c curses expat fontconfig freetype
 WANTLIB += m readline xcb z
 
-CONFIGURE_ARGS +=	--with-x
+CONFIGURE_ARGS +=	--with-x --with-fftw3=no
 
 .include <bsd.port.mk>