tatt: don't let IUSE defaults override the profile

_build_job unioned the ebuild's +flag defaults over the domain's enabled use
flags to build a package's default configuration. But pkgcore already folds
those in at their proper priority; get_package_use_unconfigured hands them
to enabled_use.pull_data as pre_defaults, below the profile and package.use,
then drops the masked ones; so unioning them back on top reinstated exactly
the flags the profile had turned off.

x11-misc/sddm carries IUSE="+elogind systemd" with REQUIRED_USE="^^ ( elogind systemd )".
On a systemd profile elogind is use.masked and enabled holds systemd, but
the union put elogind back, leaving the solver to break the ^^ against
the profile: --use-default emitted TUSE="-systemd elogind".

Drop default_on_iuse and use enabled alone, which also matches
_groupby_use_expand, already taking it as the baseline for what to print.

Resolves: #183
Signed-off-by: Arthur Zamarin <arthurzam@gentoo.org>

Author: arthurzam

NEWS.rst

@@ -34,6 +34,11 @@ pkgdev 0.2.17 (unreleased)
   solve the dependency there. Versions already stable (or already keyworded,
   for a keywordreq) on a failing arch are now passed over (Arthur Zamarin, #186)
 
+**pkgdev tatt:**
+
+- tatt: fix ebuild ``IUSE`` defaults overriding the profile when deciding a
+  package's default USE configuration (Arthur Zamarin, #183)
+
 pkgdev 0.2.16 (2026-07-31)
 --------------------------
 

src/pkgdev/scripts/pkgdev_tatt.py

@@ -280,15 +280,14 @@ def _groupby_use_expand(
 
 def _build_job(namespace, pkg, is_test: bool):
     use_expand_prefixes = tuple(s.lower() + "_" for s in namespace.domain.profile.use_expand)
-    default_on_iuse = tuple(use[1:] for use in pkg.iuse if use.startswith("+"))
     immutable, enabled, _disabled = namespace.domain.get_package_use_unconfigured(pkg)
 
     iuse = frozenset(pkg.iuse_stripped)
     force_true = immutable.union(("test",) if is_test else ())
     force_false = ("test",) if not is_test else ()
 
     if namespace.random_use == "d":
-        prefer_true = enabled.union(default_on_iuse)
+        prefer_true = enabled
     elif namespace.random_use in "rR":
         ignore_prefixes = set(namespace.ignore_prefixes)
         if namespace.random_use == "r":
@@ -303,9 +302,7 @@ def _build_job(namespace, pkg, is_test: bool):
         if prefer_true:
             random.shuffle(prefer_true)
             prefer_true = prefer_true[: random.randint(0, len(prefer_true) - 1)]
-        prefer_true.extend(
-            use for use in enabled.union(default_on_iuse) if use.startswith(ignore_prefixes)
-        )
+        prefer_true.extend(use for use in enabled if use.startswith(ignore_prefixes))
 
     # only flags REQUIRED_USE mentions need solving; the rest can't violate it
     constrained = frozenset(iter_flags(pkg.required_use))