LinuxQuestions.org - [SOLVED] Pkg-config

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Hi

I have installed pkg-config when I run

Code:

echo $PKG_CONFIG_PATH

it returns nothing. Is this correct?
The reason being I had trouble building I think makedepend, Error cant find pkg-config, FYI pkg-config was installed before starting Xwindows

Hi
I get this, but I have no idea what the correct answer should be.

Quote:

>>>echo $PKG_CONFIG_PATH
<PREFIX>/lib/pkgconfig:<PREFIX>/share/pkgconfig

Quote:

Originally Posted by spiky0011

I have installed pkg-config when I run

Code:

echo $PKG_CONFIG_PATH

it returns nothing. Is this correct?

That's interesting. I also had already installed pkg-config before starting my current BLFS system since pkg-config now is part of the LFS book. My PKG_CONFIG_PATH was probably like yours since it now is this...

Code:

$ echo $PKG_CONFIG_PATH 

/opt/qt/lib/pkgconfig

And that gets established by /etc/profile.d/qt.sh which functions to append that path to PKG_CONFIG_PATH. That script was created as part of the installation of Qt-4.8.3...

Code:

# Begin /etc/profile.d/qt.sh



QTDIR=/opt/qt



pathappend /opt/qt/bin          PATH

pathappend /opt/qt/lib/pkgconfig PKG_CONFIG_PATH



export QTDIR



# End /etc/profile.d/qt.sh

Therefore, my PKG_CONFIG_PATH must have been like yours before I installed Qt-4.8.3. In other words, empty.

The LFS book doesn't mention anything about PKG_CONFIG_PATH (except as part of the configuration for installing Libpipeline). But the BLFS book mentions it explicitly as though it should already be set...

Quote:

Originally Posted by The current BLFS book for pkg-config-0.27.1

The default setting for PKG_CONFIG_PATH is /usr/lib/pkgconfig:/usr/share/pkgconfig because of the prefix used to install pkg-config. You may add to PKG_CONFIG_PATH by exporting additional paths on your system where .pc files are installed.

I haven't had any problems of any kind related to this matter including when I installed makedepend. But I wonder if I should fix my PKG_CONFIG_PATH variable since there are .pc files located in /usr/lib/pkgconfig and /usr/share/pkgconfig. I could do that in /etc/profile. To me, it looks like something I should do.

Quote:

Originally Posted by mariostg

I get this, but I have no idea what the correct answer should be.

Quote:

>>>echo $PKG_CONFIG_PATH
<PREFIX>/lib/pkgconfig:<PREFIX>/share/pkgconfig

To me, yours is clearly wrong. It looks like you copied that from somewhere without changing <PREFIX> to what it should be. So, where did you read to do that? Just curious.

FWIW (maybe nothing), I added this to /etc/profile...

Code:

export PKG_CONFIG_PATH=/usr/lib/pkgconfig:/usr/share/pkgconfig

Now PKG_CONFIG_PATH contains the path to all three locations of my .pc files...

Code:

echo $PKG_CONFIG_PATH

/usr/lib/pkgconfig:/usr/share/pkgconfig:/opt/qt/lib/pkgconfig

I'm not saying anybody else should do this. But to me, it just looks more right. I'll see how things go from now on.

Thks stoat

That seems to have fixed it makedepend made ok, the missing .pc files were found.
Just would like to know why I had to make the adjustment.

Quote:

Originally Posted by stoat (Post 4821912)

To me, yours is clearly wrong. It looks like you copied that from somewhere without changing <PREFIX> to what it should be. So, where did you read to do that? Just curious.

I am curious too. I have no ides where the heck I got that.
grep -r "<PREFIX>/lib/pkgconfig" LFS-BOOK-7.2-NOCHUNKS.html yields nothing.

I also got that:

Code:

>>>grep -r PKG_CONFIG /etc/

/etc/profile.d/extrapaths.sh:        pathappend /usr/local/lib/pkgconfig PKG_CONFIG_PATH

/etc/profile.d/xorg.sh:pathappend $XORG_PREFIX/lib/pkgconfig PKG_CONFIG_PATH

/etc/profile.d/xorg.sh:pathappend $XORG_PREFIX/share/pkgconfig PKG_CONFIG_PATH

/etc/profile.d/xorg.sh:export PATH PKG_CONFIG_PATH

Quote:

Originally Posted by mariostg

I am curious too. I have no ides where the heck I got that.
grep -r "<PREFIX>/lib/pkgconfig" LFS-BOOK-7.2-NOCHUNKS.html yields nothing.

Well IMO, the PKG_CONFIG_PATH you posted above was closer to being right than ours. And the formatting of it with that <PREFIX> part suggested it was from an instruction in the book somewhere.

I also have the pathappend function for /usr/local/lib/pkgconfig in my extrapaths.sh script. That doesn't get added to PKG_CONFIG_PATH in my case because /usr/local/lib/pkgconfig doesn't exist in my system. But that part of extrapaths.sh implies that the PKG_CONFIG_PATH variable should already be set somewhere, and extrapaths.sh is just adding more on to it.

My Xorg.sh script doesn't have anything about PKG_CONFIG_PATH in it. It's from Xorg-7.7. The book has a version of Xorg.sh with those PKG_CONFIG_PATH lines in it when /usr is not used as the prefix for Xorg. I did use it.

So to me, all of this indicates that PKG_CONFIG_PATH should be set somewhere before /etc/profile calls those scripts in /etc/profile.d. I put the export command to do that in /etc/profile above the lines that call the scripts in /etc/profile.d. Until I learn or find out otherwise, I think that is the right thing to do.