Re: [Qemu-devel] [RFC PATCH qemu] git-submodule.sh: Do not try writing to source directory if not necessary

[Alexey Kardashevskiy]

On 26/10/17 08:11, Daniel P. Berrange wrote:
> On Wed, Oct 25, 2017 at 07:10:40PM +1100, Alexey Kardashevskiy wrote:
>> On 25/10/17 17:57, Daniel P. Berrange wrote:
>>> On Wed, Oct 25, 2017 at 12:45:10PM +1100, Alexey Kardashevskiy wrote:
>>>> On 25/10/17 03:27, Daniel P. Berrange wrote:
>>>>> On Tue, Oct 24, 2017 at 07:58:53PM +1100, Alexey Kardashevskiy wrote:
>>>>>> The new git-submodule.sh script writes .git-submodule-status to
>>>>>> the source directory every time no matter what. This makes it 
>>>>>> conditional.
>>>>>>
>>>>>> Signed-off-by: Alexey Kardashevskiy <address@hidden>
>>>>>> ---
>>>>>>
>>>>>> I compile out of tree on a remote guest system where I mount the
>>>>>> source directory as "readonly" and build directory as "rw" and
>>>>>> scripts/git-submodule.sh tries writing to the source directory even when
>>>>>> I manually update modules on a host machine which is quite annoying.
>>>>>>
>>>>>> Is this something acceptable? Or I am missing something here?
>>>>>
>>>>> How did you update the modules - did you manually run  'git submodule 
>>>>> update...'
>>>>> or did you use the git-submodule.sh script on your host machine ?
>>>>
>>>>
>>>> I run scripts/git-submodule.sh. Which is not thrilling either as I rather
>>>> expect source tree not to be affected in any way when running "make".
>>>
>>> Oh, did you pass the list of sub-modules to it when running
>>>
>>> eg, ./scripts/git-submodule.sh update ui/keycodemapdb
>>>
>>> the list of submodules you need is printed in the configure output summary.
>>
>> Sure, otherwise it does nothing.
>>
>>
>>>
>>>>> If you run git-submodule.sh on the host, then it should save the status
>>>>> file, and then when you run make on the guest system, it should notice
>>>>> that you're already updated and never even invoke 'git-submodule.sh 
>>>>> update'
>>>>
>>>>
>>>> scripts/git-submodule.sh also tries writing to the source directory (I
>>>> should probably have fixed that branch too) but this failure is not fatal
>>>> for "make" but makes it want to try "update" and then "make" fails.
>>>
>>> This shouldn't have happened in your case though, if you have already run
>>> 'git-submodule.sh update ...list of modules...' on the host machine, with
>>> the same list of modules that the guest 'configure' printed out.
>>
>> It does not matter if I run git-submodule.sh or not - "git-submodule.sh
>> status" will try writing to the read only folder anyway and it will fail
>> and Makefile's  git_module_status will be set to 1.
> 
> 
> Ahhhh, great, now I understand why you're hitting the problem !
> 
>> If I do as below (and that's what I should have done as I said), then
>> "git-submodule.sh update" is not invoked and we are good. I am not
>> reposting it yet as 1) my shell skills are crap (need to delete the temp
>> file or rewrite the whole thing not to use temp file or rewrite it in
>> python - why do not people use python everywhere?!) 2) I still hope we stop
>> doing this from Makefile :)
> 
> I agree using a tmpfile is the right fix here.


I still think not doing "git update" from Makefile is the right fix here,
is that a final decision? Why cannot "configure" do this (and ideally have
a way not to do this at all, like --no-git-submodules-update)?  Just
checking...



-- 
Alexey