All current net-fs/samba-4 ebuilds depend on dev-python/subunit. This pulls in a lot of dependencies. These are the packages that would be merged, in order: Calculating dependencies... done! [ebuild N ] dev-util/cppunit-1.13.2-r2::gentoo USE="-doc -examples -static-libs" ABI_X86="(64) -32 (-x32)" 932 KiB [ebuild N ] dev-python/pbr-1.10.0::gentoo USE="{-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 109 KiB [ebuild N ] dev-python/extras-1.0.0::gentoo USE="{-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 7 KiB [ebuild N ] dev-python/mimeparse-1.6.0::gentoo PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 7 KiB [ebuild N ] dev-python/pyrsistent-0.11.13::gentoo USE="{-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 88 KiB [ebuild N ] dev-python/linecache2-1.0.0::gentoo USE="{-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 11 KiB [ebuild N ] dev-python/traceback2-1.4.0::gentoo PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 16 KiB [ebuild N ] dev-python/unittest2-1.1.0::gentoo PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 80 KiB [ebuild N ] dev-python/testtools-2.2.0::gentoo USE="-doc {-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 226 KiB [ebuild N ] dev-python/fixtures-3.0.0::gentoo USE="{-test}" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 56 KiB [ebuild N ] sys-libs/ldb-1.1.27-r1:0/1.1.27::gentoo USE="ldap -doc" ABI_X86="(64) -32 (-x32)" PYTHON_TARGETS="python2_7" 1.241 KiB [ebuild N ] dev-libs/check-0.10.0-r2::gentoo USE="-static-libs -subunit" ABI_X86="(64) -32 (-x32)" 252 KiB [ebuild N ] dev-python/subunit-1.2.0-r1::gentoo USE="-static-libs {-test}" ABI_X86="(64) -32 (-x32)" PYTHON_TARGETS="python2_7 -pypy -pypy3 -python3_4 -python3_5" 450 KiB [ebuild N ] sys-libs/nss_wrapper-1.1.3::gentoo USE="{-test}" ABI_X86="(64) -32 (-x32)" 53 KiB [ebuild N ] sys-libs/uid_wrapper-1.2.1::gentoo USE="{-test}" ABI_X86="(64) -32 (-x32)" 305 KiB [ebuild N ] net-libs/socket_wrapper-1.1.7::gentoo USE="{-test}" ABI_X86="(64) -32 (-x32)" 54 KiB [ebuild N ] sys-libs/ntdb-1.0-r1::gentoo USE="python" ABI_X86="(64) -32 (-x32)" PYTHON_TARGETS="python2_7" 776 KiB [ebuild U ] net-fs/samba-4.2.14::gentoo [3.6.25::gentoo] USE="acl ads aio client gnutls%* ldap pam syslog system-mitkrb5%* systemd%* -addc% -addns -avahi -cluster -cups -dmapi -fam -iprint% -quota (-selinux) {-test%} -winbind (-caps%*) (-debug%) (-doc%) (-examples%) (-ldb%) (-netapi%*) (-readline%*) (-server%) (-smbclient%*) (-smbsharemodes%) (-swat%)" ABI_X86="(64) -32 (-x32)" PYTHON_TARGETS="python2_7%*" 20.400 KiB [blocks b ] <net-fs/samba-4.1.7 ("<net-fs/samba-4.1.7" is blocking sys-libs/ntdb-1.0-r1) It looks like subunit ais only needed for the testsuite [https://lists.samba.org/archive/samba-technical/2010-September/073521.html]. Perhaps the dep should oonly be pulled in when test use flag is set. On an OpenSUSE system, samba-4 compiles and runs fine without subunit installed.
Checking for system subunit : not found ERROR: System library subunit of version 0.0.0 not found, and bundling disabled * ERROR: net-fs/samba-4.2.14::gentoo failed (configure phase): My fault, so please close. Had the hope to get rid of the many python deps.