Because /usr/local/include is in the default include path, the include path and
the library path are not consistent. The consequence is that (unless the user
has modified the search paths with environment variables or switches) when some
version of a library is installed in /usr (e.g., provided by the system) and
another version of the library is installed in /usr/local (e.g., installed by
the admin with configure, make, make install), the header file will be taken
from /usr/local/include and the library will be taken from /usr/lib, but they
do not correspond to the same version.
For instance, this problem can be seen when GMP 4.1.4 is installed in /usr (as
in Debian/stable) and the user installs GMP 4.2.1 (the latest version) in
/usr/local (with configure, make, make install), as the gmp.h from GMP 4.2.1 is
not compatible with the GMP library version 4.1.4.
In short, gcc should make sure that include and library search paths are
consistent *by default*. If the user wants a different search path, he can
still modifie C_INCLUDE_PATH, LIBRARY_PATH and LD_LIBRARY_PATH (for instance)
altogether.
--
Summary: /usr/local/include should not be in the default include
path
Product: gcc
Version: 4.1.2
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: preprocessor
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: vincent at vinc17 dot org
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i486-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29588
