set deps {
  Tcl 8.6
  Tk 8.6
  Thread 2.8
  sqlite3 3.37
  tls 1.7
  logger 0.9
  md5 2.0
  tcl::chan::random 1.0
  tcl::randomseed 1.0
}

set missing {}
foreach {dep ver} $deps {
  if [catch {package require $dep $ver}] {
    lappend missing $dep $ver
  }
}

if {$missing != {}} {
  puts stderr "can't boot! missing packages!"
  foreach {dep ver} $missing {
    puts stderr "  need \"$dep\" v$ver+"
  }
  exit -1
}