Running into another system today with the fun python-exec block, I realise that while it has been discussed on the Gentoo mailing lists, and the forums slightly, there's been hardly any posts about it in the blog stream.
I'm not going to go into what caused it, but rather solutions for package conflicts in the short term, and also the long-term. The TL;DR general solution is running "emerge -1 dev-python/python-exec"
Here's the latest conflict I got on it; I wanted to install mirrorselect to compare some hosts
hostname / # emerge -pv mirrorselect
These are the packages that would be merged, in order:
[ebuild N ] net-analyzer/netselect-0.3-r3 22 kB
[ebuild U ] dev-lang/python-2.7.5-r3:2.7 [2.7.3-r2:2.7] USE="gdbm hardened%* ipv6 ncurses readline ssl threads (wide-unicode) xml -berkdb -build -doc -examples -sqlite -tk -wininst" 10,026 kB
[ebuild U ] dev-lang/python-3.2.5-r3:3.2 [3.2.3:3.2] USE="gdbm hardened%* ipv6 ncurses readline ssl threads (wide-unicode) xml -build -doc -examples -sqlite -tk -wininst" 9,020 kB
[ebuild N ] dev-lang/python-exec-2.0:2 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 79 kB
[ebuild N ] dev-util/dialog-1.2.20121230 USE="nls unicode -examples -minimal -static-libs" 422 kB
[ebuild N ] app-portage/mirrorselect-2.2.0.1 PYTHON_TARGETS="python2_7 python3_2 -python2_6 (-python3_3)" 13 kB
[blocks B ] <dev-python/python-exec-10000 ("<dev-python/python-exec-10000" is blocking dev-lang/python-exec-2.0)
Total: 6 packages (2 upgrades, 4 new), Size of downloads: 19,580 kB
Conflict: 1 block (1 unsatisfied)
* Error: The above package list contains packages which cannot be
* installed at the same time on the same system.
(dev-python/python-exec-0.2::gentoo, installed) pulled in by
dev-python/python-exec[python_targets_python2_7(-),-python_single_target_python2_5(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-)] required by (dev-libs/libxml2-2.9.0-r2::gentoo, installed)
(dev-lang/python-exec-2.0::gentoo, ebuild scheduled for merge) pulled in by
dev-lang/python-exec:=[python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-)] (dev-lang/python-exec:=[python_targets_python2_7(-),python_targets_python3_2(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-)]) required by (dev-python/setuptools-0.6.30-r1::gentoo, installed)
dev-lang/python-exec:=[python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,python_targets_python3_3(-)?,-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-)] (dev-lang/python-exec:=[python_targets_python2_7(-),python_targets_python3_2(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-)]) required by (app-portage/mirrorselect-2.2.0.1::gentoo, ebuild scheduled for merge)
dev-lang/python-exec:=[python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,python_targets_python3_3(-)?,python_targets_pypy2_0(-)?,-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-),-python_single_target_pypy2_0(-)] (dev-lang/python-exec:=[python_targets_python2_7(-),python_targets_python3_2(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-),-python_single_target_pypy2_0(-)]) required by (virtual/python-argparse-1::gentoo, installed)
For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):
http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked
This system has just dev-lang/python-exec-2.0 presently. We can reduce the conflict down to a minimal version as follows:
HOST / # emerge -pv dev-lang/python-exec
These are the packages that would be merged, in order:
[ebuild N ] dev-lang/python-exec-2.0:2 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 79 kB
[blocks B ] <dev-python/python-exec-10000 ("<dev-python/python-exec-10000" is blocking dev-lang/python-exec-2.0)
Total: 1 package (1 new), Size of downloads: 79 kB
Conflict: 1 block (1 unsatisfied)
* Error: The above package list contains packages which cannot be
* installed at the same time on the same system.
(dev-python/python-exec-0.2::gentoo, installed) pulled in by
dev-python/python-exec[python_targets_python2_7(-),-python_single_target_python2_5(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-)] required by (dev-libs/libxml2-2.9.0-r2::gentoo, installed)
(dev-lang/python-exec-2.0::gentoo, ebuild scheduled for merge) pulled in by
dev-lang/python-exec
dev-lang/python-exec:=[python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-)] (dev-lang/python-exec:=[python_targets_python2_7(-),python_targets_python3_2(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-)]) required by (dev-python/setuptools-0.6.30-r1::gentoo, installed)
dev-lang/python-exec:=[python_targets_python2_6(-)?,python_targets_python2_7(-)?,python_targets_python3_2(-)?,python_targets_python3_3(-)?,python_targets_pypy2_0(-)?,-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-),-python_single_target_pypy2_0(-)] (dev-lang/python-exec:=[python_targets_python2_7(-),python_targets_python3_2(-),-python_single_target_python2_6(-),-python_single_target_python2_7(-),-python_single_target_python3_2(-),-python_single_target_python3_3(-),-python_single_target_pypy2_0(-)]) required by (virtual/python-argparse-1::gentoo, installed)
For more information about Blocked Packages, please refer to the following
section of the Gentoo Linux x86 Handbook (architecture is irrelevant):
http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?full=1#blocked
So what do we know?
- We have dev-python/python-exec-0.2 installed, it has the default SLOT=0.
- Here's what the packages in the tree right now look like:
$ egrep '^R?DEPEND|^SLOT' dev-{python,lang}/python-exec/*ebuild
dev-python/python-exec/python-exec-10000.1.ebuild:SLOT="0"
dev-python/python-exec/python-exec-10000.1.ebuild:RDEPEND="dev-lang/python-exec:0[${PYTHON_USEDEP}]"
dev-python/python-exec/python-exec-10000.2.ebuild:SLOT="2"
dev-python/python-exec/python-exec-10000.2.ebuild:RDEPEND="dev-lang/python-exec:0[${PYTHON_USEDEP}]
dev-lang/python-exec/python-exec-0.3.1.ebuild:SLOT="0"
dev-lang/python-exec/python-exec-0.3.1.ebuild:RDEPEND="!<dev-python/python-exec-10000"
dev-lang/python-exec/python-exec-0.9999.ebuild:SLOT="0"
dev-lang/python-exec/python-exec-0.9999.ebuild:RDEPEND="!<dev-python/python-exec-10000"
dev-lang/python-exec/python-exec-2.0.ebuild:SLOT="2"
dev-lang/python-exec/python-exec-2.0.ebuild:RDEPEND="!<dev-python/python-exec-10000"
dev-lang/python-exec/python-exec-2.9999.ebuild:SLOT="2"
dev-lang/python-exec/python-exec-2.9999.ebuild:RDEPEND="!<dev-python/python-exec-10000"
If we try to bring in dev-lang/python-exec directly, it will trigger the block, because our version of dev-python/python-exec is too old.
This entire problem happens because the python*r1 eclasses bring in dev-lang/python-exec.
This leads to a simple user-actionable solution of "emerge -1 dev-python/python-exec", which will work as follows (notice that portage uninstalls the old version for us):
HOST / # emerge -pv dev-python/python-exec
These are the packages that would be merged, in order:
[ebuild N ] dev-lang/python-exec-0.3.1 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 73 kB
[ebuild N ] dev-lang/python-exec-2.0:2 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 79 kB
[uninstall ] dev-python/python-exec-0.2 PYTHON_TARGETS="(jython2_5) (jython2_7) python2_5 (python2_6) (python2_7) python3_1 (python3_2) -pypy1_9 (-pypy2_0) (-python3_3)"
[blocks b ] <dev-python/python-exec-10000 ("<dev-python/python-exec-10000" is blocking dev-lang/python-exec-2.0, dev-lang/python-exec-0.3.1)
[ebuild NS ] dev-python/python-exec-10000.2:2 [0.2:0] PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 0 kB
Total: 3 packages (2 new, 1 in new slot, 1 uninstall), Size of downloads: 152 kB
Conflict: 1 block
The above is not actually the minimal solution, but it is the best general solution. The minimal solution is to include the slot on the package, but in future if the slots change further and the default slot is removed, this won't work anymore.
HOST / # emerge -pv dev-python/python-exec:0
These are the packages that would be merged, in order:
[ebuild N ] dev-lang/python-exec-0.3.1 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 73 kB
[ebuild U ] dev-python/python-exec-10000.1 [0.2] PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3) (-pypy1_9%) (-python2_5%*) (-python3_1%*)" 0 kB
[blocks b ] <dev-python/python-exec-10000 ("<dev-python/python-exec-10000" is blocking dev-lang/python-exec-0.3.1)
Total: 2 packages (1 upgrade, 1 new), Size of downloads: 73 kB
Conflict: 1 block
But now the better question, is as developers, can we help users prevent this, and at what cost? If we don't mind new users having an extra placeholder package, then yes, we CAN actually solve it for the users. In all of the dev-lang/python-exec ebuilds we need to make this simple change:
RDEPEND="!<dev-python/python-exec-10000"
+PDEPEND=">=dev-python/python-exec-10000:$SLOT"
This provides a nice solution as follows:
# emerge -pv dev-lang/python-exec
These are the packages that would be merged, in order:
[ebuild N ] dev-lang/python-exec-0.3.1 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 73 kB
[ebuild U ] dev-python/python-exec-10000.1 [0.2] PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3) (-pypy1_9%) (-python2_5%*) (-python3_1%*)" 0 kB
[blocks b ] <dev-python/python-exec-10000 ("<dev-python/python-exec-10000" is blocking dev-lang/python-exec-2.0, dev-lang/python-exec-0.3.1)
[ebuild N ] dev-lang/python-exec-2.0:2 PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 79 kB
[ebuild NS ] dev-python/python-exec-10000.2:2 [0.2:0] PYTHON_TARGETS="(jython2_5) (jython2_7) (python2_6) (python2_7) (python3_2) (-pypy2_0) (-python3_3)" 0 kB
Total: 4 packages (1 upgrade, 2 new, 1 in new slot), Size of downloads: 152 kB
Conflict: 1 block
All that remains is convincing the Python team to accept this solution for users...
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apologize for doing this, but recent onslaught of spammers (~35 in the last 5 days) have left me with no choice: I've changed comments from non-friends to be screened by default AND require a captcha.
In the early hours of this morning, a spammer managed to get the IP of the Gentoo list server on the NiX Spam RBL... simply by spamming the subscribe address :-(. This caused approximately 2000 deliveries of normal list mail to be rejected while the server was present on the RBL.
My bicycle was stolen earlier this evening. Sufficiently close to see the guy cycling away with it. Drove around a bit with Dave looking for it, but didn't find :-(
