The proposed solution is in the tracker. If this is an autotools based package, and '--disable-silent-rules' doesn't work, you can try to add MAKEOPTS+=" V=1"
+*dahdi-2.6.1-r2 (21 Nov 2012) + + 21 Nov 2012; Tony Vroon <chainsaw@gentoo.org> +dahdi-2.6.1-r2.ebuild: + For the benefit of HFC-S PCI adapter owners, replace zaphfc (which has + stopped working) with hfcs as per Oliver Jaksch in bug #443058. Have a + supremely chatty build log as per Agostino "ago" Sarubbo in bug #443158.