Re: [gentoo-dev] bash-4.4 - call for testers

[konsolebox]

On Sun, Oct 2, 2016 at 4:58 PM, Kent Fredric <kentnl@g.o> wrote:
> On Sun, 2 Oct 2016 16:03:11 +0800
> konsolebox <konsolebox@×××××.com> wrote:
>
>> I actually don't like the idea of enabling or disabling
>> "installed-readline" based on the `${PV} != *_rc*` condition.  If a
>> user would want to explicitly enable "installed-readline" globally,
>> how would he make sure that it only affects the release version of
>> bash?  I suggest that we just don't entertain the flag (and not make
>> it available) if the ebuild is not targetting a release version, and
>> not use the readline installed by the system by default.  No one would
>> need a non-release version of bash compiled against a system readline
>> anyway.
>
> That's not what that does.  It doesn't enable or disable the mechanic,
> the code I offered only changes the default for _rc.
>
> That is, on _rc the default is "use bundled readline implementation",
> and on non_rc, the default is "use pre-existing readline
> implementation".
>
> if the user specifies an explicit
>
>     USE="system-readline"
>
> in make.conf or /etc/portage/package.use, then this "default" gets
> overridden and the system readline implementation is always used.
>
> if the user speciifies an explicit
>
>     USE="-system-readline"
>
> in make.conf or /etc/portage/package.use, then this "default" gets
> overriden and the inbuilt readline is awlays used.
>
> Explicitly defined configuration always trumps IUSE. The "+" prefix in
> IUSE only specifies that the USE flag defaults to on, as opposed to
> defaulting off.

I understand those elementary stuff, but my point was about whether we
should allow the user to configure 'system-readline' on a non-release
version of bash (i.e. make the flag available for them to configure).
Your point is that instead of statically deciding whether we shouldn't
use `--with-installed-readline` through `${PV} != *_rc*`, we instead
base it on the flag, which means we allow the users to change the
behavior of -non-release- versions of bash, which is, compiling
against the bundled readline, to compiling against the system readline
instead.

How would a user be able to apply a distinguishing global
configuration which would apply differently when the installing bash
version is a release version, and when it's not?  You might say that
`system-readline` is enabled by default in a release version anyway,
so specifying `system-readline` explicitly is meaningless and should
only be done if you want to change the behavior of non-release
versions of bash.  But that's not the point.  It's about the
consistency.  When we specify use flags in /etc/portage/make.conf, it
shouldn't depend on the current default "enability" of a package's use
flag.

Also, do you think there could be a helpful case that one would
install a non-release version of bash that compiles against the system
readline?  Perhaps if you're also brave enough to install an
pre-release version of readline to the system, there is.

Again, I say that it's better that the 'installed-readline' flag or
'system-readline' flag is only made available in the release versions
of bash.  And we also don't want to make it a dummy where it is just
ignored and not excluded.

>> I also thought using 'system-' prefix is confusing.  Does that mean
>> the system of the machine, or the system of the application?  In
>> firefox, I once thought that system-* means packages bundled within
>> it.  Perhaps I misread, or perhaps it was changed.  At that time,
>> descriptions of use flags were not widely provided yet so I could only
>> guess it based on how I built the packages.
>
> The system of the machine. As in, "Operating System". Always.
> "system-foo" usually means "foo is bundled, and toggling this flag
> toggles between using the bundled foo, or the system foo.

Yes, but I'm not talking about how it is now.  But nevermind.

>> But I don't really mind which one is used.  I also just thought
>> 'installed-readline' is better since it configures
>> `--with-installed-readline`, so one can simply have `$(use_enable
>> installed-readline)` if applicable.
>
> 'use_enable' takes a USE flag and a configure token anyway.
>
> So:
>
>     $(use_enable system-readline installed-readline)
>
> is equivalent to:
>
>      use system-readline && myconf+=" --enable-installed-readline"

I know, but like I said, "simply".  `installed-readline` is just more
relative.  But I don't really care whatever gets used.

-- 
konsolebox