What causes "invalid value for --timeout '%s'; expected seconds " in netdata/netdata?

Use an integer seconds value: `--timeout=10`

invalid value for --timeout '%s'; expected seconds

Error message

invalid value for --timeout '%s'; expected seconds

What it means

First --timeout validation failure in the network-viewer.plugin test CLI: the value contains a character outside ASCII '0'-'9' — a sign, decimal point, unit suffix, or whitespace. Exit status 2 with usage.

Source

Thrown at src/collectors/network-viewer.plugin/network-viewer.c:7039

}

static int network_viewer_set_timeout_option_once(uint64_t *slot, bool *slot_set, const char *value)
{
    if(*slot_set) {
        fprintf(stderr, "duplicate --timeout\n");
        network_viewer_test_usage(stderr);
        return 2;
    }

    if(!value || !*value) {
        fprintf(stderr, "missing value for --timeout\n");
        network_viewer_test_usage(stderr);
        return 2;
    }

    for(const char *s = value; *s; s++) {
        if(*s < '0' || *s > '9') {
            fprintf(stderr, "invalid value for --timeout '%s'; expected seconds\n", value);
            network_viewer_test_usage(stderr);
            return 2;
        }
    }

    errno = 0;
    unsigned long long parsed = strtoull(value, NULL, 10);
    if(errno == ERANGE) {
        fprintf(stderr, "invalid value for --timeout '%s'; expected seconds\n", value);
        network_viewer_test_usage(stderr);
        return 2;
    }

#if ULLONG_MAX > UINT64_MAX
    if(parsed > UINT64_MAX) {
        fprintf(stderr, "invalid value for --timeout '%s'; expected seconds\n", value);
        network_viewer_test_usage(stderr);
        return 2;

View on GitHub (pinned to 4864de85e2)

Solutions

Use an integer seconds value: `--timeout=10`
Convert unit strings to plain seconds in the calling script before passing them

Example fix

# before
network-viewer.plugin --test=network-viewer --timeout=10s
# after
network-viewer.plugin --test=network-viewer --timeout=10

Defensive patterns

Strategy: validation

Validate before calling

is_uint() { case "$1" in ''|*[!0-9]*) return 1;; *) return 0;; esac; }
is_uint "$TIMEOUT" || { echo "timeout must be plain integer seconds" >&2; exit 2; }

Prevention

Never pass unit-suffixed durations ('10s') — this CLI wants bare seconds
Strip units/convert to seconds in the calling script before building the command

When it happens

Trigger: Passing `--timeout=10s`, `--timeout=0.5`, `--timeout=-1`, or a value with an embedded space.

Common situations: Reusing durations written in netdata.conf unit syntax ('10s', '1m') where this CLI accepts bare integer seconds only.

Understand the failure class

Timeouts: ETIMEDOUT, deadlines, and hung requests — what actually expires when a request times out.

Related errors

AI-assisted analysis of netdata/netdata@4864de85e2 (2026-08-15). Data as JSON: /api/errors/263badba3e9e55e7. Report an issue: GitHub.