[sajid@xrmlite ~]$ spack install py-scipy ^python@3.6.5
==> openblas is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/openblas-0.2.20-tq4e7crjp5kedl55ubqkq5mf77kbdwbp
==> bzip2 is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/bzip2-1.0.6-hzpdm3hwavettperm3hufzmpnyzdu2bh
==> pkgconf is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/pkgconf-1.4.0-5ix6hdueykp6keate4matz6bgf6oda6k
==> ncurses is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/ncurses-6.0-5utro5xxtp2ijwnx6fiwze4qksfdi7vg
==> readline is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/readline-7.0-hlk3dniagkghsp5kmrfxloql4hht36jt
==> gdbm is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/gdbm-1.14.1-codgpslsr5agetrxl3se5mq6dxi3n7yw
==> zlib is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/zlib-1.2.11-zknfwanbwk6tnyaplsykwghx7cvnz4cr
==> openssl is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/openssl-1.0.2n-vh3oul4xm6jytrddtt4lbethwz5qbydh
==> sqlite is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/sqlite-3.22.0-y2mh46cnz457itigomsgpg2a7ymsqonv
==> python is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/python-3.6.5-ymxeu2ifh2c6fx4k2eekldpxaj2ohhp2
==> py-setuptools is already installed in /home/sajid/packages/spack/opt/spack/linux-centos7-x86_64/gcc-7.3.0/py-setuptools-39.0.1-fbz6tn5gg5qbpadih5mhgdtn3zmcnqzy
==> Error:
[sajid@xrmlite ~]$ spack install py-numpy ^python@3.6.5
==> Error:

[sajid@xrmlite ~]$ spack spec py-numpy ^python@3.6.5                                                                                                                                            
Input spec                                                                                                                                                                                      
--------------------------------                                                                                                                                                                
py-numpy                                                                                                                                                                                        
    ^python@3.6.5                                                                                                                                                                               
                                                                                                                                                                                                
Concretized                                                                                                                                                                                     
--------------------------------                                                                                                                                                                
py-numpy@1.13.3%gcc@7.3.0+blas+lapack arch=linux-centos7-x86_64                                                                                                                                 
    ^openblas@0.2.20%gcc@7.3.0 cpu_target= ~ilp64 patches=47cfa7a952ac7b2e4632c73ae199d69fb54490627b66a62c681e21019c4ddc9d +pic+shared threads=none ~virtual_machine arch=linux-centos7-x86_64  
    ^py-setuptools@39.0.1%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                                   
        ^python@3.6.5%gcc@7.3.0+dbm~optimizations patches=123082ab3483ded78e86d7c809e98a804b3465b4683c96bd79a2fd799f572244 +pic+shared~tk~ucs4 arch=linux-centos7-x86_64                        
            ^bzip2@1.0.6%gcc@7.3.0+shared arch=linux-centos7-x86_64                                                                                                                             
            ^gdbm@1.14.1%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                                    
                ^readline@7.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                               
                    ^ncurses@6.0%gcc@7.3.0 patches=4110a40613b800da2b2888c352b64c75a82809d48341061e4de5861e8b28423f,f84b2708a42777aadcc7f502a261afe10ca5646a51c1ef8b5e60d2070d926b57 ~symlinks~t
ermlib arch=linux-centos7-x86_64                                                                                                                                                                
                        ^pkgconf@1.4.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                      
            ^openssl@1.0.2n%gcc@7.3.0+systemcerts arch=linux-centos7-x86_64                                                                                                                     
                ^zlib@1.2.11%gcc@7.3.0+optimize+pic+shared arch=linux-centos7-x86_64                                                                                                            
            ^sqlite@3.22.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                                  
                                                                                                                                                                                                
[sajid@xrmlite ~]$ spack spec py-scipy ^python@3.6.5                                                                                                                                            
Input spec                                                                                                                                                                                      
--------------------------------                                                                                                                                                                
py-scipy                                                                                                                                                                                        
    ^python@3.6.5                                                                                                                                                                               
                                                                                                                                                                                                
Concretized                                                                                                                                                                                     
--------------------------------                                                                                                                                                                
py-scipy@1.0.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                                              
    ^openblas@0.2.20%gcc@7.3.0 cpu_target= ~ilp64 patches=47cfa7a952ac7b2e4632c73ae199d69fb54490627b66a62c681e21019c4ddc9d +pic+shared threads=none ~virtual_machine arch=linux-centos7-x86_64  
    ^py-numpy@1.13.3%gcc@7.3.0+blas+lapack arch=linux-centos7-x86_64                                                                                                                            
        ^py-setuptools@39.0.1%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                               
            ^python@3.6.5%gcc@7.3.0+dbm~optimizations patches=123082ab3483ded78e86d7c809e98a804b3465b4683c96bd79a2fd799f572244 +pic+shared~tk~ucs4 arch=linux-centos7-x86_64                    
                ^bzip2@1.0.6%gcc@7.3.0+shared arch=linux-centos7-x86_64                                                                                                                         
                ^gdbm@1.14.1%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                                
                    ^readline@7.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                           
                        ^ncurses@6.0%gcc@7.3.0 patches=4110a40613b800da2b2888c352b64c75a82809d48341061e4de5861e8b28423f,f84b2708a42777aadcc7f502a261afe10ca5646a51c1ef8b5e60d2070d926b57 ~symlin
ks~termlib arch=linux-centos7-x86_64                                                                                                                                                            
                            ^pkgconf@1.4.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                  
                ^openssl@1.0.2n%gcc@7.3.0+systemcerts arch=linux-centos7-x86_64                                                                                                                 
                    ^zlib@1.2.11%gcc@7.3.0+optimize+pic+shared arch=linux-centos7-x86_64                                                                                                        
                ^sqlite@3.22.0%gcc@7.3.0 arch=linux-centos7-x86_64                                                                                                                              

$ spack install py-scipy ^python@3.6.5
$ spack install py-numpy ^python@3.6.5