imagefeatures: Add test to blacklist building busybox

Now that we have a packagegroup that can be used to replace the overall
functionality of busybox as base-utils, add a test that we can continue
to build a fairly complex image without busybox being available.  This
also doubles as documentation-by-test of how to do this.

(From OE-Core rev: 6319a59c1d30eeb8ad4871d43641e3469fb543ba)

Signed-off-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/lib/oeqa/selftest/cases/imagefeatures.py

@@ -236,3 +236,29 @@ USERADD_GID_TABLES += "files/static-group"
 """
         self.write_config(config)
         bitbake("core-image-base")
+
+    def test_no_busybox_base_utils(self):
+        config = """
+# Enable x11
+DISTRO_FEATURES_append += "x11"
+
+# Switch to systemd
+DISTRO_FEATURES += "systemd"
+VIRTUAL-RUNTIME_init_manager = "systemd"
+VIRTUAL-RUNTIME_initscripts = ""
+VIRTUAL-RUNTIME_syslog = ""
+VIRTUAL-RUNTIME_login_manager = "shadow-base"
+DISTRO_FEATURES_BACKFILL_CONSIDERED = "sysvinit"
+
+# Replace busybox
+PREFERRED_PROVIDER_virtual/base-utils = "packagegroup-core-base-utils"
+VIRTUAL-RUNTIME_base-utils = "packagegroup-core-base-utils"
+VIRTUAL-RUNTIME_base-utils-hwclock = "util-linux-hwclock"
+VIRTUAL-RUNTIME_base-utils-syslog = ""
+
+# Blacklist busybox
+PNBLACKLIST[busybox] = "Don't build this"
+"""
+        self.write_config(config)
+
+        bitbake("--graphviz core-image-sato")