Running into issues with logging on Ubuntu 16.04

[tinoadams]

Running av apply --log-level debug (working) gives different result than av apply (broken).

Not providing a log level argument causes the following error:

2020-08-31 13:20:40.768 | ERROR | The command `LSLOG 10 2>&1` exited with exit code 141
2020-08-31 13:20:40.770 | ERROR | Failed

Here is a minimal example to reproduce the issue: https://github.com/tinoadams/aviary-test

[emmetog]

Also reproducible on Ubuntu 20.04:

# av apply --inventory ./infrastructure-aviary/ --log-level debug
2020-10-02 15:25:55.203 | INFO | Using local inventory /<redacted>/infrastructure-aviary
2020-10-02 15:25:55.257 | INFO | Running apply
2020-10-02 15:25:55.262 | INFO | Applying module test
2020-10-02 15:25:55.271 | DEBUG | Testing
2020-10-02 15:25:55.286 | INFO | Done
# av apply --inventory ./infrastructure-aviary/
2020-10-02 15:26:00.556 | INFO | Using local inventory /<redacted>/infrastructure-aviary
2020-10-02 15:26:00.602 | INFO | Running apply
2020-10-02 15:26:00.604 | INFO | Applying module test
2020-10-02 15:26:00.608 | ERROR | The command `LSLOG 10 2>&1` exited with exit code 141
2020-10-02 15:26:00.609 | ERROR | Failed
# lsb_release -a
No LSB modules are available.
Distributor ID:	Ubuntu
Description:	Ubuntu 20.04.1 LTS
Release:	20.04
Codename:	focal

[emmetog]

Seems to be because of this line at the very top of av:

set -euo pipefail

Removing this line seems to let things work as they should, but I'm not enough of a bash expert to know if removing it will break something else.

The actual bit of code that is breaking is here, in ./log:

  [[ $# -ne 0 ]] && _MSG="$@" || _MSG="$(cat)"
  if [[ "$LS_OUTPUT" = "/dev/stdout" ]] ; then
    echo -ne "$_LS_LEVEL_BEGIN$OUTPUT "
    echo -ne  "$_MSG"
    echo -e "$_LS_LEVEL_END"
  elif [[ "$LS_OUTPUT" = "/dev/stderr" ]] ; then
    echo -ne "$_LS_LEVEL_BEGIN$OUTPUT " >&2
    echo -ne  "$_MSG" >&2
    echo -e "$_LS_LEVEL_END" >&2
  else
    echo -ne "$_LS_LEVEL_BEGIN$OUTPUT " >> "$LS_OUTPUT"
    echo -n  "$_MSG"                    >> "$LS_OUTPUT"
    echo -e "$_LS_LEVEL_END" >> "$LS_OUTPUT"
  fi

Things break on the line echo -ne "$_MSG" >&2. Again unfortunately I'm not expert enough to suggest what the most appropriate fix is apart from removing set -euo pipefail as above.