[Buildroot] [PATCH 1/1] manual/faq: add section about why no binary packages

Mon Feb 17 22:48:20 UTC 2014

Yann,

On Mon, Feb 17, 2014 at 4:37 PM, Yann E. MORIN <yann.morin.1998 at free.fr> wrote:
> Danomi, All,
>
> On 2014-02-17 15:21 -0500, Danomi Manchego spake thusly:
>> Nit-picky writing editorial - no issue with the actual content ...
>
> Thank you!
>
> My answers below...
>
>> On Mon, Feb 17, 2014 at 12:52 PM, Yann E. MORIN <yann.morin.1998 at free.fr> wrote:
> [--SNIP--]
>> > +[[faq-no-binary-packages]]
>> > +Why doesn't Buildroot generate binary packages (.deb, .ipkg...)?
>> > +----------------------------------------------------------------
>> > +
>> > +One feature that is often discussed on the Buildroot list, is the
>>
>>  no comma
>
> Fixed.
>
>> > +the general topic of "package management". To summarize, the idea
>> > +would be to add some tracking of which Buildroot package installs
>> > +what files, with the goals of:
>> > +
>> > + * Being able to remove files installed by a package when this package
>> > +   gets unselected from the menuconfig ;
>>
>> ; -> .

It seems strange to me that a bulleted list is also considered a
complete sentence.  I think of bulleted lists like an unsorted list of
items, as opposed to a numbered list where numbers have meaning.  But
it's your party, keep as you like.

>
> I am not so sure: this is a list, and to me the second bullet-point is
> included in that sentence.
>
>> > + * Ultimately, be able to generate binary packages (ipk or other
>> > +   format) that can be installed on the target without re-generating a
>> > +   new root filesystem image.
>>
>> There's some tense inconsistency here between the first point ("Being
>> able to...") and the second ("be able to...")
>
> Fixed.
>
>> > +In general, most people think it is easy to do: just track which package
>> > +installed what and remove it when the package is unselected. However, it
>> > +is much more complicated than that:
>> > +
>> > + * It is not only about the +target/+ directory, but also the sysroot in
>> > +   +host/usr/<tuple>/sysroot+ and the +host/+ directory itself. All files
>> > +   installed in those directories by various packages must be tracked.
>> > +
>> > + * When a package is removed, it is not sufficient to remove just the
>> > +   files it installed. One must also remove all its reverse
>> > +   dependencies (i.e packages relying on it) and rebuild all those
>> > +   packages. For example, package A depends optionally on the OpenSSL
>> > +   library. Both are selected, and Buildroot is built. Package A is
>> > +   built with crypto support using OpenSSL. Later on, OpenSSL gets
>> > +   unselected from the configuration, but package A remains (since
>>
>> remains (since ,,, possible).  ->   remains.  (Since ... possible.)
>
> The phrase between parentheses is part of the previous sentence, so no
> upper-case is needed for 'since'.

I did not interpret the parenthetical content as part of the preceding
sentence - rather it seems like a complete sentence on its own.
Therefore, I thought that it should be apart from the first sentence,
with the the period inside the parenthesis.  If the parenthetic
content is really a part of the preceding sentence and does not stand
alone, then I would think that the period should be outside of the
parenthesis - as you originally had it.  But I won't press this point
any further.

Danomi -

>
> However, the english grammar rules dictate that the terminating punctuation
> be inside the parentheses, not outside. Fixed.
>
>> > +   OpenSSL is an optional dependency, this is possible). If you just
>> > +   remove the OpenSSL files, then the files installed by package A are
>> > +   broken: they use a library that is no longer present on the
>> > +   target. Technically, it is possible to do this (the prototype that
>> > +   Lionel Landwerlin and Thomas Petazzoni have worked on started to do
>> > +   this), but it is difficult and adds a fair bit of complexity.
>>
>> "a fair bit of" may be colloquial.  Maybe change to "a lot of"?
>
> Well, I like the turn of phrase, as it emphasises the fact that it is
> not easy (see eg. http://www.merriam-webster.com/dictionary/fair
> defintion 10b: moderately numerous, large, or significant).
>
>> > + * In addition to the previous problem, there is the case where the
>> > +   optional dependency is not even known to Buildroot. For example,
>> > +   package A in version 1.0 never used OpenSSL, but in version 2.0 it
>> > +   automatically uses OpenSSL if available. If the Buildroot .mk file
>> > +   hasn't been updated to take this into account, then package A will
>> > +   not be part of the reverse dependencies of OpenSSL and will not be
>> > +   removed and rebuilt when OpenSSL is removed. For sure, the .mk file
>> > +   of package A should be fixed to mention this optional dependency,
>> > +   but in the mean time, you can have non-reproducible behaviors.
>> > +
>> > + * The whole idea is also to allow changes in the menuconfig to be
>>
>> Too conversational:  "whole idea".  Maybe "idea" or "implied goal"?
>
> I've rephrased that to read:
>     The request is to also allow changes in the menuconfig [...]
>
>> > +   applied on the output directory without having to rebuild
>> > +   everything from scratch. However, this is very difficult to achieve
>> > +   in a reliable way: what happens when the suboptions of a package
>> > +   are changed (we would have to detect this, and rebuild the package
>> > +   from scratch and potentially all its reverse dependencies), what
>> > +   happens if toolchain options are changed, etc. At the moment, what
>> > +   Buildroot does is clear and simple so its behaviour is very
>> > +   reliable and it is easy to support users. If we start telling users
>> > +   that the configuration changes done in menuconfig are applied after
>>
>> "If we start telling users that" may be too conversational.  Maybe "If
>> we claim that"?
>
> I've rephrased that to read:
>     If configuration changes done in menuconfig are applied after the
>     next make [...]
>
>> > +   the next make, then it has to work correctly and properly in all
>> > +   situations, and not have some bizarre corner cases. We fear bug
>> > +   reports like "I have enabled package A, B and C, then ran make,
>
> I've rephrased "We fear bug reports like [...]" to read:
>     The risk is to get bug reports like [...]
>
>> > +   then disabled package C and enabled package D and ran make, then
>> > +   re-enabled package C and enabled package E and then there is a
>> > +   build failure". Or worse "I did some configuration, then built,
>> > +   then did some changes, built, some more changes, built, some more
>> > +   changes, built, and now it fails, but I don't remember all the
>> > +   changes I did and in which order". This will be impossible to
>> > +   support.
>> > +
>> > +For all these reasons, the conclusion is that adding tracking of
>> > +installed files to remove them when the package is unselected, or to
>> > +generate a repository of binary packages, is something that is very
>> > +hard to achieve reliably and will add a lot of complexity.
>> > +
>> > +On this matter, the Buildroot developpers make these position statements:
>>
>> developpers -> developers
>
> Fixed.
>
>> > + * Buildroot strives at making it easy to generate a root filesystem
>>
>> strives at making  ->  strives to make
>
> Fixed.
>
>> > +   (hence the name, by the way). That is what we want to make Buildroot
>> > +   good at: building root filesystems.
>> > +
>> > + * Buildroot is not meant to be a distribution (or rather, a distribution
>> > +   generator). It is the opinion of most Buildroot developers that this
>> > +   is not a goal we should pursue. We believe that there are other tools
>> > +   better suited to generate a distro than Buildroot is. For example,
>>
>> than Buildroot is.  ->  than Buildroot.
>
> In fact, not. This is a (double?) ellipsis of the adjectival clause
> 'suited to generate a distro', ellipsis which stands for (the parts
> between {} are the two ellipsises):
>     [...], than Buildroot is {suited to {generate a distro}}.
>
> If there were no adjectival clause, we would write:
>     There are other tools better than Buildroot.
>
> Thanks for the review!
>
> Regards,
> Yann E. MORIN.
>
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