exec-maven-plugin (exec:exec) output unexpected prefix for each line of stdout/stderr

[gzm55]

$ mvnd -B -Dmvnd.noBuffering=true exec:exec -Dexec.executable=uname
[INFO] [stdout] Darwin

$ mvnd -B -Dmvnd.noBuffering=true exec:exec -Dexec.executable=java -Dexec.args=-version
[WARN] [stderr] openjdk version "11.0.2" 2019-01-15
[WARN] [stderr] OpenJDK Runtime Environment 18.9 (build 11.0.2+9)
[WARN] [stderr] OpenJDK 64-Bit Server VM 18.9 (build 11.0.2+9, mixed mode)

$ mvn -B -Dmvnd.noBuffering=true exec:exec -Dexec.executable=uname
Darwin

It is reproducible on mvnd 0.8.2. The output difference breaks the script to switch to mvnd.

[gzm55]

with --raw-streams, I've got the correct result. Can we add an env/property key for this cli switch?

[gzm55]

pr #712 is closed to prefer #719.

There is another behavior difference even with --raw-streams switch:

mvnd -N exec:exec -Dexec.executable=uname --raw-streams -l a.log

The output of uname is written to tty, not a.log, whereas the original mvn writes to a.log.

[gnodet]

This is also fixed by b2bd0aa