user@host:~/filtering$ bst --option use_filter True shell hello.bst -- hello

[--:--:--][        ][    main:core activity                 ] START   Loading elements
[00:00:00][        ][    main:core activity                 ] SUCCESS Loading elements
[--:--:--][        ][    main:core activity                 ] START   Resolving elements
[00:00:00][        ][    main:core activity                 ] SUCCESS Resolving elements
[--:--:--][        ][    main:core activity                 ] START   Initializing remote caches
[00:00:00][        ][    main:core activity                 ] SUCCESS Initializing remote caches
[--:--:--][        ][    main:core activity                 ] START   Query cache
[00:00:00][        ][    main:core activity                 ] SUCCESS Query cache
[--:--:--][db2ce036][    main:hello.bst                     ] START   Staging dependencies
[00:00:00][db2ce036][    main:hello.bst                     ] SUCCESS Staging dependencies
[--:--:--][db2ce036][    main:hello.bst                     ] START   Integrating sandbox
[--:--:--][        ][    main:hello.bst                     ] START   Running commands

    ldconfig "/usr/lib"

+ sh -e -c ldconfig "/usr/lib"
[00:00:00][        ][    main:hello.bst                     ] SUCCESS Running commands
[00:00:00][db2ce036][    main:hello.bst                     ] SUCCESS Integrating sandbox
[--:--:--][db2ce036][    main:hello.bst                     ] STATUS  Running command

    hello

Hello stranger