Set CPATH in sage-env

[jdemeyer]

Since we're setting LIBRARY_PATH in sage-env (which is the compile-time equivalent of LD_LIBRARY_PATH, corresponding to the compiler flag -L), we should analogously set CPATH to SAGE_LOCAL/include (corresponding to the compiler flag -I). This is already done in the spkg-install file for sagenb-0.10.2.

Within Sage, SAGE_LOCAL effectively acts as installation prefix, so this is the logical thing to do. A GCC compiled within Sage will already look at SAGE_LOCAL/include by default.

This doesn't immediately change anything, but it will allow simplifying many spkg-install files by not having to care about -I$SAGE_LOCAL/include anymore.

Apply attachment: 13348_CPATH.patch to SAGE_ROOT.

CC: @nexttime

Component: build

Author: Jeroen Demeyer

Reviewer: Volker Braun

Merged: sage-5.4.beta2

Issue created by migration from https://trac.sagemath.org/ticket/13348

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1,3 +1,5 @@
 Since we're setting `LIBRARY_PATH` in `sage-env` (which is the *compile-time* equivalent of `LD_LIBRARY_PATH`, corresponding to the compiler flag `-L`), we should analogously set `CPATH` to `SAGE_LOCAL/include` (corresponding to the compiler flag `-I`).
 
 Within Sage, `SAGE_LOCAL` effectively acts as installation prefix, so this is the logical thing to do.  A GCC compiled within Sage will already look at `SAGE_LOCAL/include` by default.
+
+This doesn't immediately change anything, but it will allow simplifying many `spkg-install` files by not having to care about `-I$SAGE_LOCAL/include` anymore.

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1,4 +1,4 @@
-Since we're setting `LIBRARY_PATH` in `sage-env` (which is the *compile-time* equivalent of `LD_LIBRARY_PATH`, corresponding to the compiler flag `-L`), we should analogously set `CPATH` to `SAGE_LOCAL/include` (corresponding to the compiler flag `-I`).
+Since we're setting `LIBRARY_PATH` in `sage-env` (which is the *compile-time* equivalent of `LD_LIBRARY_PATH`, corresponding to the compiler flag `-L`), we should analogously set `CPATH` to `SAGE_LOCAL/include` (corresponding to the compiler flag `-I`).  This is already done in the `spkg-install` file for `sagenb-0.10.2`.
 
 Within Sage, `SAGE_LOCAL` effectively acts as installation prefix, so this is the logical thing to do.  A GCC compiled within Sage will already look at `SAGE_LOCAL/include` by default.
 

[vbraun]

Reviewer: Volker Braun

[vbraun]

comment:6

Attachment: 13348_CPATH.patch.gz

Looks good to me.