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On Wednesday 18 of May 2016 09:22:53 Andrew Savchenko wrote:
> On Mon, 02 May 2016 18:06:44 +0200 Maciej Mrozowski wrote:
> > Hello,
> >=20
> > General advise: do not convert ebuilds inheriting cmake-utils to EA=
PI 6
> > unless you know what you are doing (you are fully aware of eclass
> > behaviour removed with https://bugs.gentoo.org/show_bug.cgi?id=3D51=
4384).
> >=20
> > Background:
> >=20
> > Pre EAPI-6 cmake-utils.eclass contained certain feature to mitigate=
 CMake
> > variable case changes done by upstream.
> > This feature was explicitly removed with
> > https://bugs.gentoo.org/show_bug.cgi?id=3D514384 and no alternative=
 was
> > proposed.
> > It opened new area of possible ebuild regression bugs when switchin=
g to
> > EAPI-6 for ebuilds inheriting cmake-utils.eclass.
> >=20
> > Unfortunately there is common misconception, also among developers,=
 that
> > it's sufficient to simply replace "${cmake-utils_use_with foo)" wit=
h
> > "-DWITH_foo=3DON" etc.
> > This is MOST OF THE TIME not the case.
> > When converting cmake-utils ebuild to EAPI>=3D6, one needs to consu=
lt
> > CMakeLists.txt wrt case each variable is written with since CMake i=
s case-
> > sensitive and WITH_FOO !=3D WITH_foo !=3D WITH_Foo.
> >=20
> > Proposal:
> >=20
> > CMake allows warning about unused CMake variables passed by CLI. Si=
nce
> > this is how Gentoo passes ebuild configuration options, it's propos=
ed to
> > enable this feature.
> > Unfortunately it won't fail compilation but at least it gives a cha=
nce to
> > spot case mismatch when reading build output.
> >=20
> > Future thoughts:
> >=20
> > For better damage control it's technically possible to extend confi=
gure
> > phase of cmake-utuls eclass to check mycmakeargs against parsed pac=
kage
> > buildsystem but this might not be very reliable.
>=20
> For me the real confusion was from this line:
>=20
>     die "${FUNCNAME[1]} is banned in EAPI 6 and later: use
> -D$1${arg}=3D\"\$(usex $2)\" instead"
>=20
> It recommends to use ${arg} without any warning about case, so when I=
 just
> copied what it recommends: -DWITH_nls=3D"$(usex nls)", I had a nice s=
urprise
> and fun debugging.

Ah, there you go..

@kensington
Come on, man, you should have known better.

Invalid suggestion removed. Thanks for noticing.
I prefer to have developers figure out the right EAPI-6 migration path=20=

themselves rather than blindly relying on suggestions:

diff --git a/eclass/cmake-utils.eclass b/eclass/cmake-utils.eclass
index 427c13f..5958230 100644
=2D-- a/eclass/cmake-utils.eclass
+++ b/eclass/cmake-utils.eclass
@@ -161,7 +161,7 @@ _cmake_use_me_now() {
        local arg=3D$2
        [[ ! -z $3 ]] && arg=3D$3
=20
=2D       [[ ${EAPI} =3D=3D [2345] ]] || die "${FUNCNAME[1]} is banned in=
 EAPI 6 and=20
later: use -D$1${arg}=3D\"\$(usex $2)\" instead"
+       [[ ${EAPI} =3D=3D [2345] ]] || die "${FUNCNAME[1]} is banned in=
 EAPI 6 and=20
later"
=20
        local uper capitalised x
        [[ -z $2 ]] && die "cmake-utils_use-$1 <USE flag> [<flag name>]=
"
@@ -184,7 +184,7 @@ _cmake_use_me_now_inverted() {
        [[ ! -z $3 ]] && arg=3D$3
=20
        if [[ ${EAPI} !=3D [2345] && "${FUNCNAME[1]}" !=3D cmake-
utils_use_find_package ]] ; then
=2D               die "${FUNCNAME[1]} is banned in EAPI 6 and later: use =
=2D
D$1${arg}=3D\"\$(usex $2)\" instead"
+               die "${FUNCNAME[1]} is banned in EAPI 6 and later"
        fi
=20
        local uper capitalised x

regards
MM
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