[Mochi-devel] Mochi on Summit

[Latham, Robert J.]

On Fri, 2019-11-01 at 08:29 -0400, Abid Malik via mochi-devel wrote:
> Hello,
> 
> [amalik at login5.summit mochi]$ spack load -r margo
> ==> Error: the constraint '['margo']' matches multiple packages:
> t3x4fur margo at 0.5.2%gcc at 4.8.5 arch=linux-rhel7-power8le
> gniufvt margo at 0.5.2%gcc at 6.4.0 arch=linux-rhel7-power9le
> 
> ==> Error: In this context exactly **one** match is needed: please
> specify your constraints better.
> 
> I think it is confused by the availability of two compilers. How
> should I solve this issue?

I like Matthieu's approach best (uninstall the duplicate) but if in the
future you end up with two stacks built with two compilers, you can be
more precise in how you ask spack to load a package.

In this specific case, 'spack load -r margo%gcc at 6.4.0'  should get you
what you want.  Read on for more details.

Spack calls these "specifications" and they have captured a few
characters to help select things:
- The '@' character is a version specifier.  e.g "margo at develop" vs "
margo at 0.5.2"
- The '%' character requests a compiler "margo%gcc" or
"margo%icc".  You can further specify the compiler with an '@' to pick
a version.

Here is some more information:

https://spack.readthedocs.io/en/latest/basic_usage.html#specs-dependencies

==rob