reproduce.tt: Check for the presence of commands like nix-build

Dependencies

• [2] 5Q4ZLL37 reproduce.tt: Add --help flag
• [3] HZWUT4YN Allow users to reproduce builds on their own systems

Change contents

• replacement in src/root/reproduce.tt at line 62
  [2.1474]→[2.1474:1512](∅→∅)
  − echo "storing sources in $tmpDir" >&2
  [2.1474]

  [3.823]
  + echo "storing inputs and results in $tmpDir" >&2

  +

  +

  + requireCommand() {

  + local cmd="$1"

  + if ! type -P "$cmd" > /dev/null; then

  + echo "$0: command ‘$cmd’ is not installed; please install it and try again" >&2

  + exit 1

  + fi

  + return 0

  + }
• edit in src/root/reproduce.tt at line 85
  [3.1003]

  [3.1003]
  + echo
• edit in src/root/reproduce.tt at line 87
  [3.1120]

  [3.1120]
  + requireCommand git
• edit in src/root/reproduce.tt at line 105
  [3.1750]

  [3.1750]
  + echo
• edit in src/root/reproduce.tt at line 107
  [3.1873]

  [3.1873]
  + requireCommand hg
• edit in src/root/reproduce.tt at line 122
  [3.2302]

  [3.2302]
  + echo
• edit in src/root/reproduce.tt at line 124
  [3.2426]

  [3.2426]
  + requireCommand svn
• edit in src/root/reproduce.tt at line 156
  [3.3164]

  [3.3164]
  + requireCommand nix-build

  +
• edit in src/root/reproduce.tt at line 169
  [3.3499]

  [3.3499]
  + echo