doc: add pkg-config requirement for applications

DPDK relies on pkg-config(1) to provide correct parameters for
compiler and linker used in application build.  Inaccurate build
parameters, produced by pkg-config from DPDK .pc files could fail
application build or cause unpredicted results during application
runtime.

Update system requirements doc about a bug in pkg-config v0.27
used in RHEL-7.

Signed-off-by: Gregory Etelson <getelson@nvidia.com>
Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>

diff --git a/doc/guides/linux_gsg/sys_reqs.rst b/doc/guides/linux_gsg/sys_reqs.rst
index 7e41075..e074faf 100644 (file)
--- a/doc/guides/linux_gsg/sys_reqs.rst
+++ b/doc/guides/linux_gsg/sys_reqs.rst
@@ -92,6 +92,19 @@ found in that driver's documentation in the relevant DPDK guide document,
 e.g. :doc:`../nics/index`
 
 
+Building DPDK Applications
+--------------------------
+
+The tool pkg-config or pkgconf, integrated in most build systems,
+must be used to parse options and dependencies from libdpdk.pc.
+
+.. note::
+
+   pkg-config 0.27, supplied with RHEL-7,
+   does not process the Libs.private section correctly,
+   resulting in statically linked applications not being linked properly.
+
+
 Running DPDK Applications
 -------------------------