Re: [PATCH] trace-cmd: Add Requires: libtracefs to libtracecmd.pc file

[Yordan Karadzhov <y.karadz@gmail.com>]

On 10.11.21 г. 18:17 ч., Steven Rostedt wrote:
> On Wed, 10 Nov 2021 16:12:12 +0200
> Yordan Karadzhov <y.karadz@gmail.com> wrote:
> 
>> On 9.11.21 г. 18:14 ч., Steven Rostedt wrote:
>>> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
>>>
>>> In order to not have users of libtracecmd having to also include the
>>> includes and libraries for libtracefs and libraceevent, add a requires
>>> field for libtracefs to the libtracecmd.pc file. As libtracefs requires
>>> libtraceevent, it will pull that one in as well.
>>>
>>> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
>>> ---
>>>    libtracecmd.pc.template | 1 +
>>>    scripts/utils.mk        | 1 +
>>>    2 files changed, 2 insertions(+)
>>>
>>> diff --git a/libtracecmd.pc.template b/libtracecmd.pc.template
>>> index dc41076e..bcf4e39d 100644
>>> --- a/libtracecmd.pc.template
>>> +++ b/libtracecmd.pc.template
>>> @@ -6,5 +6,6 @@ Name: libtracecmd
>>>    URL: https://git.kernel.org/pub/scm/utils/trace-cmd/trace-cmd.git/
>>>    Description: Library for creating and reading trace-cmd data files
>>>    Version: LIB_VERSION
>>> +Requires: libtracefs >= LIBTRACEFS_MIN_VERSION
>>
>> BTW this works also without the 'lib' prefix:
>>
>> Requires: tracefs >= LIBTRACEFS_MIN_VERSION
> 
> I just tried that on Fedora, and get this:
> 
> # pkg-config --libs libtracecmd
> Package tracefs was not found in the pkg-config search path.
> Perhaps you should add the directory containing `tracefs.pc'
> to the PKG_CONFIG_PATH environment variable
> Package 'tracefs', required by 'libtracecmd', not found

OK, it looks like what matters is really the name of the .pc file (and the 'Name: ...' line). I was confused because 
'json-c.ps' has no 'lib' prefix. Looking into

/usr/local/lib/x86_64-linux-gnu/pkgconfig

I see that most of the configuration files do not have 'lib', however there is also a number of files starting with 
'lib'. I wonder if there is some rule about using this 'lib' prefix.

Thanks!
Yordan


> 
> -- Steve
>