Ruby error on some platforms

I get this error on some platforms when running LVS using the Sky130 PDK:

sh: line 1: pmap: command not found
ERROR: In /home/X/class/chip-tutorials/klayout/tech/sky130/pymacros/../lvs/sky130.lvs: undefined method strip' for nil:NilClass ERROR: /home/X/class/chip-tutorials/klayout/tech/sky130/pymacros/run_lvs.lym:135: RuntimeError: NoMethodError: undefined methodstrip' for nil:NilClass in Executable::execute
/home/X/class/chip-tutorials/klayout/tech/sky130/pymacros/../lvs/sky130.lvs:27:in block in execute' /nix/store/c4bdx4dja3h06xg1ksv3f51alp5a44li-ruby-3.1.5/lib/ruby/3.1.0/logger.rb:586:informat_message'
/nix/store/c4bdx4dja3h06xg1ksv3f51alp5a44li-ruby-3.1.5/lib/ruby/3.1.0/logger.rb:476:in add' /nix/store/c4bdx4dja3h06xg1ksv3f51alp5a44li-ruby-3.1.5/lib/ruby/3.1.0/logger.rb:529:ininfo'
/home/X/class/chip-tutorials/klayout/tech/sky130/pymacros/../lvs/sky130.lvs:34:in execute' :/built-in-macros/lvs_interpreters.lym:31:ininstance_eval'
:/built-in-macros/lvs_interpreters.lym:31:in `execute' in Macro.run
/home/X/class/chip-tutorials/klayout/tech/sky130/pymacros/run_lvs.lym:135

I've confirmed that it works on:
Ubuntu 20.04 with Ruby 2.7.1

But it fails on:
Ubuntu 20.04 with Ruby 3.1.5 (inside Docker)
MacOS Sequoia 15 with Ruby 2.6.10

I have a demo with an inverter.