Various prereq fixes

[jdemeyer]

• Allow Sage to build on Cygwin without setting SAGE_PORT.
• Don't check for sqrtl() which is apparently not needed (Cygwin doesn't have it, yet Sage builds).
• Remove all checks for the deprecated variable SAGE_FORTRAN_LIB.
• Remove AC_ARG_VAR(SAGE_FORTRAN) which is a deprecated variable.
• Check for tar before actually untarring the prereq tarball (originally Test for a GNU tar on Solaris is broken #14407), only do these checks if SAGE_PORT is unset.

Copy http://boxen.math.washington.edu/home/jdemeyer/spkg/prereq-1.2.tar.gz to spkg/base (diff)

Apply attachment: trac_14406+reviewer-v3.patch

CC: @jdemeyer @nexttime @jpflori

Component: porting

Author: Jeroen Demeyer, Jean-Pierre Flori

Reviewer: Jean-Pierre Flori, Jeroen Demeyer

Merged: sage-5.9.beta4

Issue created by migration from https://trac.sagemath.org/ticket/14406

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1 +1,4 @@
 Allow Sage to build on Cygwin without setting `SAGE_PORT`.
+
+While we're at it:
+* remove all checks for the deprecated variable `SAGE_FORTRAN_LIB`.

[jdemeyer]

Author: Jeroen Demeyer

[jdemeyer]

Description changed:

--- 
+++ 
@@ -1,4 +1,5 @@
-Allow Sage to build on Cygwin without setting `SAGE_PORT`.
-
-While we're at it:
-* remove all checks for the deprecated variable `SAGE_FORTRAN_LIB`.
+* Allow Sage to build on Cygwin without setting `SAGE_PORT`.
+* Don't check for `sqrtl()` which is apparently not needed (Cygwin doesn't have it, yet Sage builds).
+* Remove all checks for the deprecated variable `SAGE_FORTRAN_LIB`.
+* Remove `AC_ARG_VAR(SAGE_FORTRAN)` which is a deprecated variable.
+* Check for `tar` before actually untarring the prereq tarball (originally #14407).

[jdemeyer]

Description changed:

--- 
+++ 
@@ -2,4 +2,4 @@
 * Don't check for `sqrtl()` which is apparently not needed (Cygwin doesn't have it, yet Sage builds).
 * Remove all checks for the deprecated variable `SAGE_FORTRAN_LIB`.
 * Remove `AC_ARG_VAR(SAGE_FORTRAN)` which is a deprecated variable.
-* Check for `tar` before actually untarring the prereq tarball (originally #14407).
+* Check for `tar` before actually untarring the prereq tarball (originally #14407), only do these checks if `SAGE_PORT` is unset.

[jdemeyer]

Description changed:

--- 
+++ 
@@ -3,3 +3,7 @@
 * Remove all checks for the deprecated variable `SAGE_FORTRAN_LIB`.
 * Remove `AC_ARG_VAR(SAGE_FORTRAN)` which is a deprecated variable.
 * Check for `tar` before actually untarring the prereq tarball (originally #14407), only do these checks if `SAGE_PORT` is unset.
+
+**Copy** [http://boxen.math.washington.edu/home/jdemeyer/spkg/prereq-1.2.tar.gz](http://boxen.math.washington.edu/home/jdemeyer/spkg/prereq-1.2.tar.gz) to `spkg/base` ([diff](https://github.com/sagemath/sage-prod/files/10657539/prereq-1.2.diff.gz))
+
+**Apply** [attachment: 14406_cygwin_prereq.patch](https://github.com/sagemath/sage-prod/files/10657540/14406_cygwin_prereq.patch.gz)

[jdemeyer]

comment:5

Attachment: prereq-1.2.diff.gz