Ludovic Courtès <l...@gnu.org> writes: > 宋文武 <iyzs...@gmail.com> skribis: > >> Ludovic Courtès <l...@gnu.org> writes: >> >>> With commit dbc31ab, it is now possible to do things like: >>> >>> eval `guix package --search-paths=suffix` >>> >>> to augment the search path environment variables instead of overriding >>> them. >> Doesn't the KIND field belong to 'search-path-specification'? >> Some variables are exact (GDK_PIXBUF_MODULE_FILE, GTK_DATA_PREFIX, etc.) >> by definition. > > What do you mean? > > Here ‘exact’ means: > > export PATH=/foo > > whereas ‘prefix’ means: > > export PATH=/foo:$PATH > > This is not a property of the ‘PATH’ variable, but rather a choice that > the user can make. OK. > > What makes ‘GDK_PIXBUF_MODULE_FILE’ particular? From the name I’m > guessing it is *not* a search path, but rather is meant to specify a > single file. This is not what ‘search-path-specification’ is for, at > least in its current form. Yes, that's right. > >> I'd like to add 'GTK_DATA_PREFIX' and 'GTK_EXE_PREFIX' to gtk+ >> as 'exact' native-search-paths. >> They generate value to profile as: >> - /run/current-system/profile, if you have installed xfce system wide. >> - ~/.guix-profile, if you installed xfce into user's profile. >> So, the GTK+ themes will work out-of-box. > > Likewise, it seems that these are not search paths. > > This is not the first time there’s this temptation to use > ‘search-path-specification’ for things that are not search paths. > Clearly there seems to be a need for a similar mechanism, but we need to > find a way for formalize it. Hm, currently the 'search-paths' is the only way for a specified package to populate environment variables into profile (and builder). I tend to think 'search-paths' are designed for build, but they are unually useful (and same) for profile too. > > One way might be to augment ‘search-path-specification’ to support > “single-item search paths” that basically designate a single file. > Yes, but some conflicted inputs will bring headahce to builder. For 'GDK_PIXBUF_MODULE_FILE', both gdk-pixbuf and librsvg have loaders.cache file, how we ensure the one from librsvg is selected?
> Or we could come up with a different mechanism, but it’s not clear to me > what that would be. I have no idea about now too. Thanks!
