Linux link error on master branch

[teotwawki]

For the past couple weeks I've been seeing a linker error on builds against github master:

Linking CXX executable opencpn
/usr/bin/ld: libNMEA0183.a(nmea.cpp.o): undefined reference to symbol 'dlsym@@GLIBC_2.2.5'
/usr/bin/ld: note: 'dlsym@@GLIBC_2.2.5' is defined in DSO /lib64/libdl.so.2 so try adding it to the linker command line

This is on Fedora 16, using cmake 2.8.8. The root of the problem seems to be a commit on 9/30, which was intended to "Correct CMake library linkage rules for some linux builds". Unfortunately, removing dl breaks the build on my particular linux

commit 428eb654f19f15eecef731bb04fb716684e0229d
Author: David Register <bdbcat@users.sourceforge.net>
Date:   Sun Sep 30 21:41:14 2012 -0400

    Correct CMake library linkage rules for some linux builds, esp. Debian

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 509bbdc..63293b0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -776,13 +776,9 @@ ENDIF(UNIX)
 
 #   Certain older Cmake FindGTK2 modules ( e.g. cmake-2.8.0-2) do not yield all
 #   So, add them manually.
-IF(UNIX AND NOT APPLE)
-TARGET_LINK_LIBRARIES(${PACKAGE_NAME}
-      dl
-      gobject-2.0
-)
-ENDIF(UNIX AND NOT APPLE)
+IF(GTK2_FOUND)
+TARGET_LINK_LIBRARIES( ${PACKAGE_NAME} gobject-2.0 )
+ENDIF(GTK2_FOUND)

[SethDart]

Same here :-(
I put a comment on the commit https://github.com/OpenCPN/OpenCPN/c...fb716684e0229d.
Wayting for Dave answer...

For now, you can revert the commit:
$ git revert 428eb654f19f15eecef731bb04fb716684e0229d

Or execute
$ export LDFLAGS="$LDFLAGS -ldl"
before running cmake

[rooiedirk]

My gentoo / Sabayon machine does't have the errors.

[bdbcat]

Good Morning....

OK, easy fix. I have been trying to simplify the CMake script, and remove platform dependencies wherever possible.

As Einstein is said to have said:
"Make things as simple as possible, and no simpler."

And that's why we do Beta testing....

Dave

[teotwawki]

Latest master takes care of the problem -- thanks Dave.