my test matrix is down to
```
clang      = ['10.0.0', '9.0.1', '8.0.0', '7.1.0', '7.0.1', '6.0.1']
gcc        = ['9.3.0', '9.2.0', '9.1.0', '8.4.0', '8.3.0', '8.2.0', '8.1.0', '7.4.0', '7.3.0', '7.2.0', '7.1.0']
boost      = ['1.72.0', '1.71.0', '1.70.0', '1.69.0', '1.68.0', '1.67.0']
hwloc      = ['2.1.0', '2.0.2']
jemalloc   = ['5.2.1']
gperftools = ['2.7']
otf2       = ['2.2']
```