buildah unshare + tclsh

buildah-snippet.tcl

RUN buildah unshare tclsh << [list apply {{container} {
    source ./utils.tcl

    set mntDir [@RUN buildah mount $container]

    set prefix sysroot

    foreach dir [lgrep-match $prefix/* [git-submodule-list .]] {
        set destDir $mntDir/[regsub ^$prefix $dir {}]
        git-clone-submodule-as-workdir $dir $destDir
    }
}} $container]

RUN buildah unshare tclsh << [list apply {{container} {
    source ./utils.tcl

    set mntDir [@RUN buildah mount $container]

    set argv [list $mntDir]

    source ./populate.tcl

}} $container]

# RUN emits stdout and stderr as-is
proc RUN args {
    puts [list RUNNING: $args]
    exec -ignorestderr {*}$args >@ stdout 2>@ stderr
}

# @RUN captures stdout and return it
proc @RUN args {
    puts [list RUNNING: $args]
    exec -ignorestderr {*}$args 2>@ stderr
}