The result of spack spec is not super consistent and depends on the flags used. This makes debugging lengthy build failures (e.g., py-torch) difficult...

Steps to reproduce the issue

$ spack spec    gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
$ spack spec -I gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
$ spack --debug --stacktrace spec    gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
$ spack --debug --stacktrace spec -I gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer

1. spack spec ... command resolves diffutils and ncurses to arch=cray-cnl5-bulldozer:

   spack spec gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer

    
    Input spec
    --------------------------------
    gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
   
    Concretized
    --------------------------------
    ==> Warning: Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors
    gettext@0.21%gcc@5.3.0+bzip2+curses+git~libunistring+libxml2+tar+xz arch=cray-suse_linux11-bulldozer
        ^bzip2@1.0.8%gcc@5.3.0+shared arch=cray-suse_linux11-bulldozer
            ^diffutils@3.7%gcc@5.3.0 arch=cray-cnl5-bulldozer
                ^libiconv@1.16%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
        ^libxml2@2.9.10%gcc@5.3.0~python arch=cray-suse_linux11-bulldozer
            ^pkgconf@1.7.4%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
            ^xz@5.2.5%gcc@5.3.0~pic arch=cray-suse_linux11-bulldozer
            ^zlib@1.2.11%gcc@5.3.0+optimize+pic+shared arch=cray-suse_linux11-bulldozer
        ^ncurses@6.2%gcc@5.3.0~symlinks+termlib abi=none arch=cray-cnl5-bulldozer
        ^tar@1.34%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    

2. spack spec -I ... command resolves bzip2, libiconv, xz, zlib, and ncurses to arch=cray-cnl5-bulldozer:

   spack spec -I gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer

    
    Input spec
    --------------------------------
    -   gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
   
    Concretized
    --------------------------------
    ==> Warning: Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors
    -   gettext@0.21%gcc@5.3.0+bzip2+curses+git~libunistring+libxml2+tar+xz arch=cray-suse_linux11-bulldozer
    [+]      ^bzip2@1.0.8%gcc@5.3.0+shared arch=cray-cnl5-bulldozer
    [+]          ^diffutils@3.7%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    [+]              ^libiconv@1.16%gcc@5.3.0 arch=cray-cnl5-bulldozer
    -       ^libxml2@2.9.10%gcc@5.3.0~python arch=cray-suse_linux11-bulldozer
    [+]          ^pkgconf@1.7.4%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    [+]          ^xz@5.2.5%gcc@5.3.0~pic arch=cray-cnl5-bulldozer
    [+]          ^zlib@1.2.11%gcc@5.3.0+optimize+pic+shared arch=cray-cnl5-bulldozer
    [+]      ^ncurses@6.2%gcc@5.3.0~symlinks+termlib abi=none arch=cray-cnl5-bulldozer
    [+]      ^tar@1.34%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    

3. spack --debug --stacktrace spec command resolves bzip2, libiconv,pkgconf, zlib, and ncurses to arch=cray-cnl5-bulldozer:

   spack --debug --stacktrace spec gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer

    lib/spack/spack/util/executable.py:188 ==> [2021-04-08-10:54:00.287407] '/bin/bash' '--norc' '--noprofile' '-lc' 'echo $CRAY_CPU_TARGET'
    lib/spack/spack/platforms/cray.py:154 ==> [2021-04-08-10:54:00.306459] default to front-end architecture
    lib/spack/spack/cmd/__init__.py:122 ==> [2021-04-08-10:54:00.466622] Imported spec from built-in commands
    lib/spack/spack/cmd/__init__.py:122 ==> [2021-04-08-10:54:00.468600] Imported spec from built-in commands
    Input spec
    --------------------------------
    gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    Concretized
    --------------------------------
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:00.475995] Reading config file /dev/shm/spack/test/etc/spack/defaults/config.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:00.550154] Reading config file /dev/shm/spack/test/etc/spack/config.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:00.559828] Reading config file /u/staff/mbelkin/.spack/config.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:01.539299] Reading config file /dev/shm/spack/test/etc/spack/defaults/repos.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:01.546097] Reading config file /dev/shm/spack/test/etc/spack/repos.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:02.983742] Reading config file /dev/shm/spack/test/etc/spack/compilers.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:04.806201] Reading config file /dev/shm/spack/test/etc/spack/defaults/packages.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-10:54:04.907017] Reading config file /dev/shm/spack/test/etc/spack/packages.yaml
    dev/shm/spack/test/lib/spack/spack/main.py:431 ==> [2021-04-08-10:54:05.868855] Warning: Intel's compilers may or may not optimize to the same degрee for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.186875] opt_criterion(15, version weight)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.187378] opt_criterion(14, number of non-default variants (roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.187777] opt_criterion(13, multi-valued variants + preferred providers for roots)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.188175] opt_criterion(11, number of non-default variants (non-roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.188569] opt_criterion(9, number of non-default providers (non-roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.188961] opt_criterion(8, count of non-root multi-valued variants)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.189354] opt_criterion(7, compiler matches + number of nodes)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.189762] opt_criterion(6, version badness)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.190156] opt_criterion(5, non-preferred compilers)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.190547] opt_criterion(4, target matches)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-10:54:10.190939] opt_criterion(3, non-preferred targets)
    lib/spack/spack/database.py:364 ==> [2021-04-08-10:54:10.212736] DATABASE LOCK TIMEOUT: 3s
    lib/spack/spack/database.py:368 ==> [2021-04-08-10:54:10.213675] PACKAGE LOCK TIMEOUT: No timeout
    gettext@0.21%gcc@5.3.0+bzip2+curses+git~libunistring+libxml2+tar+xz arch=cray-suse_linux11-bulldozer
        ^bzip2@1.0.8%gcc@5.3.0+shared arch=cray-cnl5-bulldozer
            ^diffutils@3.7%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
                ^libiconv@1.16%gcc@5.3.0 arch=cray-cnl5-bulldozer
        ^libxml2@2.9.10%gcc@5.3.0~python arch=cray-suse_linux11-bulldozer
            ^pkgconf@1.7.4%gcc@5.3.0 arch=cray-cnl5-bulldozer
            ^xz@5.2.5%gcc@5.3.0~pic arch=cray-suse_linux11-bulldozer
            ^zlib@1.2.11%gcc@5.3.0+optimize+pic+shared arch=cray-cnl5-bulldozer
        ^ncurses@6.2%gcc@5.3.0~symlinks+termlib abi=none arch=cray-cnl5-bulldozer
        ^tar@1.34%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    

4. spack --debug --stacktrace spec -I command resolves libiconv and xz to arch=cray-cnl5-bulldozer:

   spack --debug --stacktrace spec gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer

    
    lib/spack/spack/util/executable.py:188 ==> [2021-04-08-11:22:13.590133] '/bin/bash' '--norc' '--noprofile' '-lc' 'echo $CRAY_CPU_TARGET'
    lib/spack/spack/platforms/cray.py:154 ==> [2021-04-08-11:22:13.610731] default to front-end architecture
    lib/spack/spack/cmd/__init__.py:122 ==> [2021-04-08-11:22:13.802151] Imported spec from built-in commands
    lib/spack/spack/cmd/__init__.py:122 ==> [2021-04-08-11:22:13.804152] Imported spec from built-in commands
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:13.808353] Reading config file /dev/shm/spack/test/etc/spack/defaults/config.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:13.881523] Reading config file /dev/shm/spack/test/etc/spack/config.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:13.891616] Reading config file /u/staff/mbelkin/.spack/config.yaml
    lib/spack/spack/database.py:364 ==> [2021-04-08-11:22:13.914982] DATABASE LOCK TIMEOUT: 3s
    lib/spack/spack/database.py:368 ==> [2021-04-08-11:22:13.915445] PACKAGE LOCK TIMEOUT: No timeout
    Input spec
    --------------------------------
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:13.993712] Reading config file /dev/shm/spack/test/etc/spack/defaults/repos.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:14.000272] Reading config file /dev/shm/spack/test/etc/spack/repos.yaml
     -   gettext@0.21%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    Concretized
    --------------------------------
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:16.414900] Reading config file /dev/shm/spack/test/etc/spack/compilers.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:18.230479] Reading config file /dev/shm/spack/test/etc/spack/defaults/packages.yaml
    lib/spack/spack/config.py:981 ==> [2021-04-08-11:22:18.332947] Reading config file /dev/shm/spack/test/etc/spack/packages.yaml
    dev/shm/spack/test/lib/spack/spack/main.py:431 ==> [2021-04-08-11:22:19.302837] Warning: Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.475782] opt_criterion(15, version weight)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.476663] opt_criterion(14, number of non-default variants (roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.477074] opt_criterion(13, multi-valued variants + preferred providers for roots)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.477476] opt_criterion(11, number of non-default variants (non-roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.477872] opt_criterion(9, number of non-default providers (non-roots))
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.478268] opt_criterion(8, count of non-root multi-valued variants)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.478662] opt_criterion(7, compiler matches + number of nodes)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.479056] opt_criterion(6, version badness)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.479450] opt_criterion(5, non-preferred compilers)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.479842] opt_criterion(4, target matches)
    lib/spack/spack/solver/asp.py:1566 ==> [2021-04-08-11:22:23.480237] opt_criterion(3, non-preferred targets)
     -   gettext@0.21%gcc@5.3.0+bzip2+curses+git~libunistring+libxml2+tar+xz arch=cray-suse_linux11-bulldozer
    [+]      ^bzip2@1.0.8%gcc@5.3.0+shared arch=cray-suse_linux11-bulldozer
    [+]          ^diffutils@3.7%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    [+]              ^libiconv@1.16%gcc@5.3.0 arch=cray-cnl5-bulldozer
     -       ^libxml2@2.9.10%gcc@5.3.0~python arch=cray-suse_linux11-bulldozer
    [+]          ^pkgconf@1.7.4%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    [+]          ^xz@5.2.5%gcc@5.3.0~pic arch=cray-cnl5-bulldozer
    [+]          ^zlib@1.2.11%gcc@5.3.0+optimize+pic+shared arch=cray-suse_linux11-bulldozer
     -       ^ncurses@6.2%gcc@5.3.0~symlinks+termlib abi=none arch=cray-suse_linux11-bulldozer
    [+]      ^tar@1.34%gcc@5.3.0 arch=cray-suse_linux11-bulldozer
    
    

Error Message

None

Information on your system

spack debug report

• Spack: 0.16.1-2136-68cec598dc
• Python: 3.7.9
• Platform: cray-suse_linux11-bulldozer
• Concretizer: clingo

Additional information

• I have run spack debug report and reported the version of Spack/Python/Platform
• I have searched the issues of this repo and believe this is not a duplicate
• I have run the failing commands in debug mode and reported the output