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On 03/11/2012 06:55 PM, Brian Harring wrote: |
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> On Sat, Mar 10, 2012 at 08:06:50AM -0800, Zac Medico wrote: |
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>> Yeah. Another way of putting it is that the requirement to spawn a bash |
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>> process and source the ebuild adds a ridiculous amount of unnecessary |
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>> complexity, in violation of the KISS principle [1]. |
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> |
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> This statement is incorrect. |
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> |
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> Even if EAPI could be parsed via some non sourcing approach, we |
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> *still* have to source the ebuild to get the metadata for when the |
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> EAPI is supported (the vast majority of usage). That complexity is |
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> there one way or another- we wouldn't be trying to extract the EAPI |
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> from the ebuild unless the cache was invalid/missing. |
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There are a couple of other cases worth considering: |
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1) User downloads an overlay that doesn't provide cache. We want the |
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package manager to give a pretty "EAPI unsupported" message, rather than |
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spit out some bash syntax errors. |
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2) You're assuming that a package manager can validate cache for an EAPI |
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that it doesn't necessarily support. That's a somewhat fragile |
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assumption, given the complexities of cache validation, which involve |
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verification all files that affect metadata and those files may vary |
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depending on the EAPI. |
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> Phrasing it more bluntly: you can only avoid the sourcing step if you |
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> can isolate that the EAPI is unsupported (which is extremely rare in |
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> terms of actual user experience). For the rest of the time (well past |
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> the 99% mark) sourcing is the immediate step following. |
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For the sake of being robust in all possible cases, it's just a lot |
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simpler if we can obtain the EAPI simply and reliably, without spawning |
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bash to source the ebuild. |
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> Also, stop referencing wikipedia. People know what "trivial |
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> objection" and "KISS" is. |
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You can't assume that. On this list we've got potential to have readers |
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and responders with lots of different backgrounds. Your insistence on |
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using bash to obtain the EAPI would make me wonder if you understood the |
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KISS principle, if I didn't know you better. |
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-- |
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Thanks, |
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Zac |
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