[gentoo-pms] Write to filesystem in pkg_* phases

[Ulrich Mueller]

This topic was already discussed in -dev some time ago [1], but went
nowhere at the time. Now it came up again in bug 469210 [2].
(Ironically, checking for a particular kernel configuration is the
example mentioned in the spec for pkg_pretend.)

We say in Table 11.1 [3] that T and TMPDIR (and HOME) are legal in all
phases and must be "the location of a usable temporary directory". At
the same time, we say in the spec for pkg_* phases that they "must not
write to the filesystem" [4], or that they "must not write outside of
the directories specified by the ROOT and D environment variables" [5]
which effectively forbids writing to the ${T} etc. directories.

What is the purpose of this restriction? From above mentioned bug I
conclude that neither Portage nor Paludis enforce it.

Ulrich


[1] https://archives.gentoo.org/gentoo-dev/msg_ea6dce57c39ff597afdca7ba74f7cc73.xml
[2] https://bugs.gentoo.org/show_bug.cgi?id=469210
[3] http://dev.gentoo.org/~ulm/pms/5/pms.html#x1-118002
[4] http://dev.gentoo.org/~ulm/pms/5/pms.html#x1-960009.1.2
[5] http://dev.gentoo.org/~ulm/pms/5/pms.html#x1-1040009.1.10