*** goredo [2023-10-01 13:53]:
>What was the error?

One of the variables with *os.File was out of scope and garbage
collector could collect it and variable's finalizer will close
the file descriptor, that invalidly could be reused in a wrong way.
That problem arose only when I dealt with thousands of targets and
dependencies, which presumably pressures garbage collector more,
leading to unexpected behaviour with files. I did not see target's
output corruption, but building may fail.

-- 
Sergey Matveev (http://www.stargrave.org/)
OpenPGP: 12AD 3268 9C66 0D42 6967  FD75 CB82 0563 2107 AD8A