[petsc-dev] Configure won't find python

[Satish Balay]

I guess this is an alternate way to implement this logic..

diff --git a/configure b/configure
index 4538314871..8dddfed05d 100755
--- a/configure
+++ b/configure
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!./python-detect
 
 import sys, os
 
diff --git a/python-detect b/python-detect
new file mode 100755
index 0000000000..1fdfe795c8
--- /dev/null
+++ b/python-detect
@@ -0,0 +1,6 @@
+#!/bin/sh
+for pyimpl in python3 python2 python ; do
+   command -v $pyimpls > /dev/null && echo Using: $pyimpl && exec $pyimpl "$@"
+done
+echo “Could not locate python! Please have python3 python2 or python in PATH
+exit 2


Satish

On Fri, 17 Apr 2020, Jacob Faibussowitsch wrote:

> Hello All,
> 
> I use an Ubuntu docker image based on jedbrown/mpich-ccache and ran into the following error (Dockerfile attached as well).
> 
> If in a user only has python3 installed and not python2 then /usr/bin/python doesn’t exist. Given that python2 has gone the way of the dodo perhaps petsc should be looking for python3 over python2. This is a somewhat funky but functioning implementation that replaces the shebang line in configure that I have been using to default to python3. I don’t know how portable it is however, I believe “command" is not universally available in every shell?
> 
> #!/bin/sh
> 
> # “”” is comment in python, and : is noop in shell so this configure can be run as ./configure and python2.7 ./configure
> """:"
> 
> # Find the right python implementation, check by sending it on over to dave
> for pyimpls in python3 python2 python /usr/bin/python /usr/bin/env python ; do
>    command -v > /dev/null $pyimpls && exec $pyimpls $0 "$@“
> done
> 
> # Error code in case things go awry
> 
> Echo “PYTHON NOT FOUND” >2
> 
> exit 2
> 
> ":"""
> 
> if sys.version_info < (2,6) or (sys.version_info >= (3,0) and sys.version_info < (3,4)):
>   print('************************************************************************')
>   print('*      Python version 2.6+ or 3.4+ is required to run ./configure      *')
>   print('*         Try: "python2.7 ./configure" or "python3 ./configure"        *')
>   print('************************************************************************')
>   sys.exit(4)
> 
> sys.path.insert(0, os.path.abspath('config'))
> import configure
> configure.petsc_configure([])
> 
> 
> Best regards,
> 
> Jacob Faibussowitsch
> (Jacob Fai - booss - oh - vitch)
> Cell: (312) 694-3391
> 
>