venvbst2  will  localhost  ~  projects  buildstream  keytest  willsalmon/sandboxarch  $  bst -o target_arch aarch64 build basic-import.bst
[15:59:48][--:--:--][        ][    main:core activity                 ] START   Build
[15:59:48][--:--:--][        ][    main:core activity                 ] START   Loading elements
[15:59:48][00:00:00][        ][    main:core activity                 ] SUCCESS Loading elements
[15:59:48][--:--:--][        ][    main:core activity                 ] START   Resolving elements
[15:59:48][00:00:00][        ][    main:core activity                 ] FAILURE Resolving elements
[15:59:48][00:00:00][        ][    main:core activity                 ] FAILURE Build


Unknown architecture: %{target_arch}