When the goroutines used in the library are schedule unfavorably, Stdout will be set after starting the command. However, in the absence of a user provided pipe, the crypto/ssh library itself sets Stdout to ioutil.Discard, triggering the error that we want to set Stdout again, which is not possible.
The proposed PR solves this issue by creating the pipe outside a goroutine which ensures that no race condition exists between running the command and creating the stdout pipe.
bramvdbogaerde
commented
3 years ago
Summary from PR:
When the goroutines used in the library are schedule unfavorably,
Stdoutwill be set after starting the command. However, in the absence of a user provided pipe, thecrypto/sshlibrary itself setsStdouttoioutil.Discard, triggering the error that we want to setStdoutagain, which is not possible.The proposed PR solves this issue by creating the pipe outside a goroutine which ensures that no race condition exists between running the command and creating the stdout pipe.