portage curly brace use flag for test [SOLVED]

[sinfree]

It appears that sometimes portage shows use flags with curly braces surrounding the flag.
It appears that "USE=-flag" has no effect on such a flag.
After two days of searching over internet I ask : is this feature documented in gentoo?

example:
USE="-test" emerge opensp
answer:
circular dependency
It might be possible to break the cycle
by applying the following change
- app-text/opensp-1.5.2-r3 (changed USE: -test)

[sinfree]

As stated in https://devmanual.gentoo.org/general-concepts/dependencies/index.html
saying:
Post-Merge Dependencies

The PDEPEND variable specifies dependencies which must be merged after the package. This is sometimes used for plugins which have a dependency upon the package being merged. Generally PDEPEND should be avoided in favour of RDEPEND except where this will create circular dependency chains.

should I change RDEPEND to PDEPEND for app-text/opensp dependency in openjade ebuild?

[sinfree]

If I modify the ebuild to add the PDEPEND modification how do I avoid package corruption?

[sinfree]

The digest option seems to avoid portage corruption from being noticed.
But the circular dependency continues to block upgrade.

[rh1]

The Dev guide isn't quite accurate. Packages listed in PDEPEND in an ebuild are not guarenteed to be emerged after that package. See https://bugs.gentoo.org/show_bug.cgi?id=424117 . As far as corruption the best solution is to create an overlay and stick your modified ebuild in it.

[sinfree]

These solutions appears to be bad solutions as they are too complex to be implied:
the circular dependency appears each time the package openjade is used.
It blocks my world update.
There should be a simple solution avoiding developing tchniques.

[sinfree]

The simple solution is to ask package maintainer to correct their ebuild, but it has a time effect on package upgrade as it blocks world upgrade.

What should be temporary work around?

[sinfree]

If I want to signal ebuild problem where can I find ebuild maintainer email?

[sinfree]

"test" flag has conditional flag in opensp; why I cannot disable it with USE="-test"?

[sinfree]

USE="-test" is what emerge preconises, so what else?

[sinfree]

--changed-use
Tells emerge to include installed packages where USE flags have changed since installation. This option also implies the --selective option. Unlike --newuse, the --changed-use option does not trigger reinstallation when flags that the user has not enabled are added or removed.
NOTE: This option ignores the state of the "test" USE flag, since that flag has a special binding to FEATURES="test" (see make.conf(5) for more information about FEATURES settings).

So that USE="-test" has no effect as changed-use cannot affect test.

I have to modify FEATURES settings, just web browsing a little more...

[sinfree]

The USE variable has no effect on test.

But FEATURES can,

so
FEATURES="-test" emerge opensp

can unlock
emerge --update world