Re: Problem building a version update of rng-tools

[Michael Tremer <michael.tremer@ipfire.org>]

[-- Attachment #1: Type: text/plain, Size: 5619 bytes --]

Hey,

That is probably a good idea :)

-Michael

> On 3 May 2023, at 17:09, Adolf Belka <adolf.belka(a)ipfire.org> wrote:
> 
> Hi Michael,
> 
> On 03/05/2023 17:57, Adolf Belka wrote:
>> Hi Michael,
>> 
>> On 03/05/2023 17:39, Michael Tremer wrote:
>>> Hello Adolf,
>>> 
>>>> On 3 May 2023, at 14:23, Adolf Belka <adolf.belka(a)ipfire.org> wrote:
>>>> 
>>>> Hi Michael,
>>>> 
>>>> On 03/05/2023 14:58, Adolf Belka wrote:
>>>>> 
>>>>> On 03/05/2023 14:35, Adolf Belka wrote:
>>>>>> Hi Michael,
>>>>>> 
>>>>>> On 03/05/2023 14:07, Michael Tremer wrote:
>>>>>>> Hello Adolf,
>>>>>>> 
>>>>>>> Normally you should not need to add anything extra for this to work. The compiler should know where to search for libraries.
>>>>>>> 
>>>>>>> If pkg-config is being used, this might be a little bit different.
>>>>>> Just before the various packages are checked to exist the configure also checks that pkg-config is existing.
>>>>>>> 
>>>>>>>> On 3 May 2023, at 13:02, Adolf Belka <adolf.belka(a)ipfire.org> wrote:
>>>>>>>> 
>>>>>>>> Hi All,
>>>>>>>> 
>>>>>>>> 
>>>>>>>> There is a new version for rng-tools so I thought I would do an update but it kept stopping saying that it required libcap and could not find it.
>>>>>>>> 
>>>>>>>> I noted that the libcap libs are in /lib and not in /usr/lib as the other packages that rng-tools looks for have their libs. (openssl, libxml2, curl, jansson)
>>>>>>>> 
>>>>>>>> The new version has a flag for the ./configure called libcap_LIBS which can be used to override pkg-config.
>>>>>>>> 
>>>>>>>> I tried that in various ways such as libcap_LIBS="/lib" or libcap_LIBS="/lib/libcap.so.2.67" and others, but none of them worked. The ./configure still ended up with the message
>>>>>>>> 
>>>>>>>> checking for libcap... no
>>>>>>>> configure: error: libcap is required
>>>>>>>> 
>>>>>>>> I then noticed that libcap.pc is in /lib/pkgconfig/ while all the other packages being searched for are in /usr/lib/pkgconfig/
>>>>>>> 
>>>>>>> This should indeed be installed to /usr/lib/pkgconfig.
>>>>>>> 
>>>>>>> I don’t have a problem with simply changing —-prefix=/ to —-prefix=/usr for libcap, because we don’t support a split /usr directory anyways. That should make it easier.
>>>>> Looking through the libcap README and Makefile then the .pc files should be getting placed in /usr/lib/pkgconfig but they aren't. Also as $(prefix) is not defined then the prefix should be /usr but again it is not.
>>>> 
>>>> I think I must have misread what the Makefile etc were intending to do.
>>>> 
>>>> I just tried a quick build of libcap with adding prefix=/usr to the make and make install lines and the lib files and the .pc files are now in /usr/lib/ and /usr/lib/pkgconfig/
>>>> 
>>>> The only remaining question I have is if anything else in IPFire would be expecting to see the lib files for libcap in /lib/ instead of /usr/lib/ because then the symlinking of the lib from /lib/ to /usr/lib/ won't be needed any more.
>>> 
>>> No, pkg-config should never search in /lib.
>> Okay, that is good to know.
>>> 
>>>> What is libcap used for so I can test out the built iso on a vm machine?
>>> 
>>> It is quite widely used to manage capabilities of a running program. I can give some privileges away and limit itself so that any remote code executing could not cause too much damage for example.
>>> 
>>> /usr/bin/ping is for example linked against libcap. If you can execute it, everything is fine.
>> That is a nice easy test then.
>> 
>> The build of libcap with prefix=/usr successfully built but it also placed the capsh, getcap, getpcaps and setcap binaries from /sbin to /usr/sbin so the change was not as easy as I thought. Maybe I should only have the prefix=/usr in the make line and not in the make install line.
>> 
>> Will have another look in the makefile and see how the location for capsh etc are defined.
>> 
> Discovered that I also had to define exec_prefix as blank, then those executable files were placed in /sbin again.
> 
> 
> Regards,
> 
> Adolf.
> 
>> Regards,
>> Adolf.
>>> 
>>>> Regards,
>>>> 
>>>> Adolf.
>>>> 
>>>>>> libcap currently keeps the library files in /lib/ but makes a symlink to one of them in /usr/lib/. Libcap doesn't have a configure line. There is a sed command on the Makefile to stop it building static libs and then it goes straight to make and then make install
>>>>>>> 
>>>>>>>> I then manually did a copy of libcap.pc to /usr/lib/pkgconfig/ and then re ran just the rng-tools build and it then successfully found libcap and completed the build. So the problem is definitely to do withy the unusual location for the library files of libcap.
>>>>>>> 
>>>>>>> Do we have any other packages that install .pc files into funny places?
>>>>>> The other .pc files that are in /lib/pkgconfig/ are libkeyutils, libproc-2, libpsx and libsysfs
>>>>>>> 
>>>>> The libpsx.pc file is also from libcap.
>>>>>>>> So the question I have is what is the best way to deal with this.
>>>>>>>> 
>>>>>>>> Should I add into the libcap lfs a line that copies the libcap.pc to /usr/lib/pkgconfig/ or
>>>>>>>> 
>>>>>>>> is can someone tell me what I am doing wrong with the libcap_LIBS flag for ./configure
>>>>>>>> 
>>>>> I think that rather than trying to adjust libcap to work the way it says it should be anyway, I will add a copy line into the lfs to move the libcap.pc file to /usr/lib/pkgconfig/
>>>>> 
>>>>> 
>>>>> Regards,
>>>>> 
>>>>> Adolf.
>>>>> 
>>>>>>>> 
>>>>>>>> Regards,
>>>>>>>> 
>>>>>>>> Adolf.
>>>>>>>> 
>>>>>>> 
>>>>>>> -Michael