diff --git a/include/gargoyle.h b/include/gargoyle.h
index 70c2da0..ceac561 100644
--- a/include/gargoyle.h
+++ b/include/gargoyle.h
@@ -2,10 +2,11 @@
 #define __GARGOYLE_H_
 
 #include <gargoyle/codex.h>
+#include <gargoyle/delusion.h>
 #include <gargoyle/privledge.h>
 #include <stdint.h>
 
-uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc, char ***argv, gargoyle_flag_type flags);
-uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const char *prefix, uint16_t prefix_sz, char ***envh, gargoyle_flag_type flags);
+uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc, char ***argv, struct gargoyle_err *err, gargoyle_flag_type flags);
+uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const char *prefix, uint16_t prefix_sz, char ***envh, struct gargoyle_err *err, gargoyle_flag_type flags);
 
 #endif
diff --git a/include/gargoyle/codex.h b/include/gargoyle/codex.h
index cb0ec3a..d7f146b 100644
--- a/include/gargoyle/codex.h
+++ b/include/gargoyle/codex.h
@@ -13,13 +13,13 @@ static const gargoyle_opt_type GARGOYLE_TYPE_ROPE = 1 << 4;
 
 typedef uint8_t gargoyle_err_type;
 
-static const gargoyle_err_type GARGOYLE_ERR_SUCCESS = 1 << 0;
-static const gargoyle_err_type GARGOYLE_ERR_UNKNOWN_OPT = 1 << 1;
-static const gargoyle_err_type GARGOYLE_ERR_VALUE_REQUIRED = 1 << 2;
-static const gargoyle_err_type GARGOYLE_ERR_INVALID_UINT = 1 << 3;
-static const gargoyle_err_type GARGOYLE_ERR_INVALID_SINT = 1 << 4;
-static const gargoyle_err_type GARGOYLE_ERR_INVALID_DBLE = 1 << 5;
-static const gargoyle_err_type GARGOYLE_ERR_UNKNOWN_TYPE = 1 << 6;
+static const gargoyle_err_type GARGOYLE_ERR_SUCCESS = 0;
+static const gargoyle_err_type GARGOYLE_ERR_UNKNOWN_OPT = 1 << 0;
+static const gargoyle_err_type GARGOYLE_ERR_VALUE_REQUIRED = 1 << 1;
+static const gargoyle_err_type GARGOYLE_ERR_INVALID_UINT = 1 << 2;
+static const gargoyle_err_type GARGOYLE_ERR_INVALID_SINT = 1 << 3;
+static const gargoyle_err_type GARGOYLE_ERR_INVALID_DBLE = 1 << 4;
+static const gargoyle_err_type GARGOYLE_ERR_UNKNOWN_TYPE = 1 << 5;
 
 typedef uint8_t gargoyle_flag_type;
 
diff --git a/src/gargoyle.c b/src/gargoyle.c
index a72c549..7d05f24 100644
--- a/src/gargoyle.c
+++ b/src/gargoyle.c
@@ -3,8 +3,10 @@
 #include <gargoyle/sleuth.h>
 #include <gargoyle/twine.h>
 #include <stddef.h>
+#include <stdio.h>
+#include <string.h>
 
-uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc, char ***argv, gargoyle_flag_type flags) {
+uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc, char ***argv, struct gargoyle_err *err, gargoyle_flag_type flags) {
   if(!(flags & GARGOYLE_FLG_GREED)) {
     *argc -= 1;
     *argv += 1;
@@ -14,6 +16,8 @@ uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc
     flags |= GARGOYLE_FLG_ICASE;
   }
 
+  gargoyle_cpy(err->func, __func__, GARGOYLE_MAX_FUNC_SZ, GARGOYLE_FLG_FILL0);
+
   while(1) {
     const char *arg = **argv;
 
@@ -33,6 +37,9 @@ uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc
 
       if(!opt) {
         if(flags & GARGOYLE_FLG_STRCT) {
+          err->code = GARGOYLE_ERR_UNKNOWN_OPT;
+          char *eql = index(brand, '=');
+          snprintf(err->msg, GARGOYLE_MAX_ERR_SZ, "unknown option --%.*s", (int) (eql - brand), brand);
           return GARGOYLE_ERR_UNKNOWN_OPT;
         } else {
           *argc -= 1;
@@ -102,7 +109,7 @@ uint8_t gargoyle_digest_argv(uint16_t optc, struct gargoyle_opt *optv, int *argc
   return GARGOYLE_ERR_SUCCESS;
 }
 
-uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const char *prefix, uint16_t prefix_sz, char ***envh, gargoyle_flag_type flags) {
+uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const char *prefix, uint16_t prefix_sz, char ***envh, struct gargoyle_err *err, gargoyle_flag_type flags) {
   if(flags & GARGOYLE_FLG_BCASE) {
     flags |= GARGOYLE_FLG_ICASE;
   }
@@ -119,6 +126,9 @@ uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const cha
 
     if(!opt) {
       if(flags & GARGOYLE_FLG_STRCT) {
+        err->code = GARGOYLE_ERR_UNKNOWN_OPT;
+        char *eql = index(brand, '=');
+        snprintf(err->msg, GARGOYLE_MAX_ERR_SZ, "unknown option %.*s", (int) (eql - brand), brand);
         return GARGOYLE_ERR_UNKNOWN_OPT;
       } else {
         continue;
@@ -138,5 +148,5 @@ uint8_t gargoyle_digest_envh(uint16_t optc, struct gargoyle_opt *optv, const cha
     }
   }
 
-  return 0;
+  return GARGOYLE_ERR_SUCCESS;
 }