[1/1] force rsync of local package and try to rebuild it with its dependencies

The purpose of this patch is to force rsync of local site packages and
rebuild them if their source code has changed. Therefore, if the source
of a package has changed, it will be rebuild if you type make or
make <pkg>. Likewise, if a package has a library dependency which is
local site package too and you type make <pkg>, the library will be
rebuild if the source has been modified.

This behavior is pretty useful if you use buildroot with many of your
own packages. Especially if you share these packages with a developer
team through a version control system like git.

Signed-off-by: Anthony Viallard <viallard@syscom-instruments.com>
---
 package/pkg-generic.mk | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

Dear Anthony Viallard,

On Thu,  2 Jul 2015 11:15:15 +0200, Anthony Viallard wrote:
> The purpose of this patch is to force rsync of local site packages and
> rebuild them if their source code has changed. Therefore, if the source
> of a package has changed, it will be rebuild if you type make or
> make <pkg>. Likewise, if a package has a library dependency which is
> local site package too and you type make <pkg>, the library will be
> rebuild if the source has been modified.
> 
> This behavior is pretty useful if you use buildroot with many of your
> own packages. Especially if you share these packages with a developer
> team through a version control system like git.

Again, I don't think we want this change in Buildroot. I don't think we
want *all* local packages to systematically be rsync'ed and rebuilt, at
every "make" invocation.

Maybe we want a separate "make rebuild-local" target (not sure of the
name), which would trigger this special action. Local packages could be
all registered in a global LOCAL_PACKAGES variable, and make
rebuild-local would rebuild them all.

Note that you could also solve this problem by adding something like
that in your external.mk (provided you're using BR2_EXTERNAL):

# Needs to be filled in with your complete list of packages
CUSTOM_PACKAGES = foo1 foo2 foo3

rebuild-custom: $(foreach p,$(CUSTOM_PACKAGES),$(p))

> -	rsync -au $(RSYNC_VCS_EXCLUSIONS) $(SRCDIR)/ $(@D)
> +	rsync -au $(RSYNC_VCS_EXCLUSIONS) --include core $(SRCDIR)/ $(@D)

This change is unrelated to the patch I believe.

Best regards,

Thomas

On 07/02/15 12:35, Thomas Petazzoni wrote:
> Dear Anthony Viallard,
> 
> On Thu,  2 Jul 2015 11:15:15 +0200, Anthony Viallard wrote:
>> The purpose of this patch is to force rsync of local site packages and
>> rebuild them if their source code has changed. Therefore, if the source
>> of a package has changed, it will be rebuild if you type make or
>> make <pkg>. Likewise, if a package has a library dependency which is
>> local site package too and you type make <pkg>, the library will be
>> rebuild if the source has been modified.
>>
>> This behavior is pretty useful if you use buildroot with many of your
>> own packages. Especially if you share these packages with a developer
>> team through a version control system like git.
> 
> Again, I don't think we want this change in Buildroot. I don't think we
> want *all* local packages to systematically be rsync'ed and rebuilt, at
> every "make" invocation.

 Actually, why not? Ideally, we would like to rebuild everything every time -
but that just takes too long. However, we can assume that there aren't so many
local packages, so their rebuild does not necessarily take too long.

 So I went and did an experiment on my laptop (HDD, 8GB RAM, so relatively
slow): when nothing actually has to be rebuilt, 'make linux-rebuild' takes 40s
longer than 'make linux'. (I'm taking linux because that's the one where we can
expect the most overhead from rebuilding.)  That is the same amount of time as
building a small package like xz.

 Conclusion: indeed, we shouldn't do rebuilding of local packages by default.

> 
> Maybe we want a separate "make rebuild-local" target (not sure of the
> name), which would trigger this special action. Local packages could be
> all registered in a global LOCAL_PACKAGES variable, and make
> rebuild-local would rebuild them all.
> 
> Note that you could also solve this problem by adding something like
> that in your external.mk (provided you're using BR2_EXTERNAL):

 Or in your local.mk (BR2_PACKAGE_OVERRIDE_FILE), where you put these overrides.

> 
> # Needs to be filled in with your complete list of packages
> CUSTOM_PACKAGES = foo1 foo2 foo3
> 
> rebuild-custom: $(foreach p,$(CUSTOM_PACKAGES),$(p))

 Or if you don't want to call a specific target:

world: $(foreach p,$(CUSTOM_PACKAGES),$(p))

That way, you can just type 'make' and it will rebuild your custom packages.


> 
>> -	rsync -au $(RSYNC_VCS_EXCLUSIONS) $(SRCDIR)/ $(@D)
>> +	rsync -au $(RSYNC_VCS_EXCLUSIONS) --include core $(SRCDIR)/ $(@D)
> 
> This change is unrelated to the patch I believe.

 And it should be added to RSYNC_VCS_EXCLUSIONS instead.

 However, why is this even needed? RSYNC_VCS_EXCLUSIONS doesn't exclude any
pattern that matches 'core'.


 Regards,
 Arnout


> 
> Best regards,
> 
> Thomas
>