Terminate after warning is thrown - global setting

General Usage
,
1

I want to ensure that my program runs without doing questionable operations. Thus I would like the program to terminate whenever a warning is thrown; i.e. promote a warning to the level of errors.

Is there a way to do this? I have the Python equivalent warnings.filterwarnings("error") of the warnings package in mind.

2

Julia doesn’t “throw” warnings. However, warning messages are typically written to the stderr stream, so you can turn such warnings to errors simply by redirecting stderr to a read-only stream:

julia> redirect_stderr(open(touch(tempname()), "r"))
IOStream(<file ...>)

julia> @warn "foo"
ERROR: ArgumentError: write failed, IOStream is not writeable

(With a bit more work, I guess you could change stderr to a pipeline of some sort that captures the warning message and re-prints it.)

1 Like
3

You can install a custom logger that eg. terminates the process for messages with level higher than warnings:

julia> using Logging, LoggingExtras

julia> terminator = EarlyFilteredLogger(global_logger()) do log_args
           if log_args.level >= Logging.Warn
               println(stderr, "ERROR: Log message with higher level than Logging.Warn, terminating process.")
               exit(-1)
           end
           return true
       end;

julia> global_logger(terminator);

julia> @info "hello"
[ Info: hello

julia> @warn "world"
ERROR: Log message with higher level than Logging.Warn, terminating process.

$ # back to shell prompt
3 Likes
4

I suppose there is a way to add a trace back to this fine solution ?
regards,

5

If you just want to promote the level from warning to error you can do that with a custom logger too, but as Steven said, error log messages don’t terminate the process (@error "something" is not the same as error("something")):

julia> using LoggingExtras, Logging

julia> promoter = TransformerLogger(global_logger()) do log_args
           if Logging.Error > log_args.level >= Logging.Warn
               return merge(log_args, (; level = Logging.Error))
           else
               return log_args
           end
       end;

julia> global_logger(promoter);

julia> @info "hello"
[ Info: hello

julia> @warn "warn"
┌ Error: warn
└ @ Main REPL[11]:1
1 Like
6

Like all errors it should render a stacktrace if uncaught.
But if you are just raising it to @error level you can put in the stacktrace in the transformer logger manually.
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