nginx/nginx · error

NGX_LOG_EMERG

NGX_LOG_EMERG

Error message

invalid variable name \"$\"

What it means

Error "invalid variable name \"$\"" thrown in nginx/nginx.

Source

Thrown at src/http/ngx_http_variables.c:434

    ngx_http_variable("");
ngx_http_variable_value_t  ngx_http_variable_true_value =
    ngx_http_variable("1");


static ngx_uint_t  ngx_http_variable_depth = 100;


ngx_http_variable_t *
ngx_http_add_variable(ngx_conf_t *cf, ngx_str_t *name, ngx_uint_t flags)
{
    ngx_int_t                   rc;
    ngx_uint_t                  i;
    ngx_hash_key_t             *key;
    ngx_http_variable_t        *v;
    ngx_http_core_main_conf_t  *cmcf;

    if (name->len == 0) {
        ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                           "invalid variable name \"$\"");
        return NULL;
    }

    if (flags & NGX_HTTP_VAR_PREFIX) {
        return ngx_http_add_prefix_variable(cf, name, flags);
    }

    cmcf = ngx_http_conf_get_module_main_conf(cf, ngx_http_core_module);

    key = cmcf->variables_keys->keys.elts;
    for (i = 0; i < cmcf->variables_keys->keys.nelts; i++) {
        if (name->len != key[i].key.len
            || ngx_strncasecmp(name->data, key[i].key.data, name->len) != 0)
        {
            continue;
        }

View on GitHub (pinned to 3f6f7824d4)

When it happens

Trigger: Thrown at src/http/ngx_http_variables.c:434 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of nginx/nginx@3f6f7824d4 (2026-08-22). Data as JSON: /api/errors/9ebcae6f970ef02c. Report an issue: GitHub.