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Hello all, |
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I see two problems with the implementations that were suggested up to now for |
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per-package environment variables. |
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1) They do not allow any flexibility with regard to package versions, as |
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opposed to other Portage configuration files ("package.mask", "package.use", |
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etc.). The file "/etc/portage/packages.env/app-shells/bash" would be sourced |
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for all versions of "app-shells/bash", for instance. This may be problematic |
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for SLOTable packages, and prevents a user from defining or modifying a |
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variable for a particular version of a package (to work around a bug, for |
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example, such as "pymol-0.95" will segfault when raytracing if compiled with |
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"-fgcse"). |
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|
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2) Having a hierarchy of files and directories miroring the Portage tree, with |
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symlinks and such, looks a bit complicated more complicated than is needed. |
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I'd rather have to deal with only one or a few files. |
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My initial suggestion was not flexible enough, since it required to declare |
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the variables repeatedly for each package. Here is another idea: |
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A file named "/etc/portage/package.env" could contain entries such as: |
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|
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app-office/openoffice lang_ru |
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>=app-sci/emboss-2.8.0 icc |
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=app-sci/pymol-0.95* gcc_low_opt |
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|
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The keywords "lang_ru", "ifc" and "gcc_low_opt" would match files with these |
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names, contained in "/etc/portage/env.d". These bash scripts would be sourced |
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to provide per-package env vars. "/etc/portage/env.d/icc" would contain |
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something along these lines: |
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CC=icc |
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CXX=icc |
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CFLAGS="-O2 -xN -noalign" |
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CXXFLAGS=$CFLAGS |
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USE="icc" |
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|
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If we wanted to make things even easier to configure, we could have something |
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like the following in "/etc/portage/package.env": |
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|
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=app-sci/pymol-0.95* [ CC="gcc" CFLAGS="-O1" ] |
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|
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... were a keyword is replaced by a delimited short bash script that would be |
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sourced to provide per package env vars. This would avoid having to create |
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files in "/etc/portage/env.d" which target only one package. |
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I don't think this approach is elegant or powerful. A better mechanism would |
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allow to filter and replace flags (like flag-o-matic), to choose compilers |
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and have them merged as dependencies when needed, etc. However, per-package |
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env vars would be enough in 99 % of the cases, and would extend farther than |
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just compilers and compiler flags. |
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|
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-- |
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Olivier Fisette (ribosome) |
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Gentoo Linux Developer |
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