Hello, As Sid Hayn raised today on #gentoo-portage, it would be useful to finally have portage able to fetch updates from VCS-es independently of src_unpack(). This could be used, for example, on machines temporarily connected to the network -- one would then fetch files while connected to the network, and perform the updates later.
There are a few ways how we could handle that but the cleanest and most universal one seems to be defining a src_fetch() phase function in a future EAPI. In the EAPIs supporting src_fetch(), that phase function would be used by PM when requesting the files to be fetched. A default_src_fetch() will be declared as well, providing implementation-defined code fetching files like they are fetched now. Older EAPIs will simply always use that default. The phase function would be disjoint from the normal merge process, much like pkg_pretend(). In portage, it will be called as 'portage' user if FEATURES=userfetch is enabled. VCS eclasses supporting separated fetching would define two phase functions: - src_fetch() which would be responsible for fetching updates, - src_unpack() which would be responsible for checking out the source to work directory. The remaining issue is handling dependencies on the tools necessary to do fetching. For default_src_fetch(), we can assume that the package manager provides the necessary tools. For custom src_fetch(), we would need either to: 1) require satisfying whole DEPEND when fetching -- probably pointless, as it will make --fetchonly almost impossible when doing initial installs; 2) introduce a new dependency type (please do not get into details how we do it -- we will discuss that another time, at the moment please just keep it as 'new dependency type') -- and we probably end up having a switch for --fetchonly without installing deps (thus omitting packages where they are not satisfied), and with deps; 3) [ugly!] assume that src_fetch() should check for its deps and fail if they are not satisfied. If that's mostly for live ebuilds, it may be acceptable. Then the package manager will just have one 'fetch failed' on --fetchonly (or early pre-fetch), and it will have to invoke src_fetch() after satisfying the deps, before src_unpack(). What do you think? What are your ideas, suggestions? -- Best regards, Michał Górny
signature.asc
Description: PGP signature
