diff --git a/src/debug.h b/src/debug.h
index ead92b24..c99b7003 100644
--- a/src/debug.h
+++ b/src/debug.h
@@ -26,6 +26,9 @@
 #include <stdint.h>
 #endif
 
+#include "gpgme.h"  /* Required for gpgme_error stuff.  */
+
+
 /* Indirect stringification, requires __STDC__ to work.  */
 #define STRINGIFY(v) #v
 #define XSTRINGIFY(v) STRINGIFY(v)
@@ -81,6 +84,13 @@ void _gpgme_debug_buffer (int lvl, const char *const fmt,
 void _gpgme_debug_frame_begin (void);
 void _gpgme_debug_frame_end (void);
 
+static inline gpgme_error_t
+_gpgme_trace_gpgme_error (gpgme_error_t err, const char *file, int line)
+{
+  _gpgme_debug (DEBUG_ENGINE, "%s:%d: returning error: %s\n",
+                _gpgme_debug_srcname (file), line, gpgme_strerror (err));
+  return err;
+}
 
 
 /* Trace support.  */
@@ -262,4 +272,11 @@ void _gpgme_debug_frame_end (void);
   _gpgme_debug_end (&(hlp))
 #define TRACE_ENABLED(hlp) (!!(hlp))
 
+/* And finally a simple macro to trace the location of an error code.
+   This macro is independent of the other trace macros and may be used
+   without any preconditions.  */
+#define trace_gpg_error(e) \
+  _gpgme_trace_gpgme_error (gpg_error (e), __FILE__, __LINE__)
+
+
 #endif	/* DEBUG_H */
diff --git a/src/decrypt.c b/src/decrypt.c
index f4f95dc9..63787c70 100644
--- a/src/decrypt.c
+++ b/src/decrypt.c
@@ -146,7 +146,7 @@ parse_enc_to (char *args, gpgme_recipient_t *recp)
   if (*args != '\0' && *args != ' ')
     {
       free (rec);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
 
   while (*args == ' ')
@@ -160,7 +160,7 @@ parse_enc_to (char *args, gpgme_recipient_t *recp)
 	{
 	  /* The crypto backend does not behave.  */
 	  free (rec);
-	  return gpg_error (GPG_ERR_INV_ENGINE);
+	  return trace_gpg_error (GPG_ERR_INV_ENGINE);
 	}
     }
 
@@ -283,7 +283,7 @@ _gpgme_decrypt_status_handler (void *priv, gpgme_status_code_t code,
 	  }
 	/* FIXME: Is this ok?  */
 	if (!rec)
-	  return gpg_error (GPG_ERR_INV_ENGINE);
+	  return trace_gpg_error (GPG_ERR_INV_ENGINE);
       }
       break;
 
diff --git a/src/delete.c b/src/delete.c
index 283b3e60..37e54f89 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -48,7 +48,7 @@ delete_status_handler (void *priv, gpgme_status_code_t code, char *args)
       gpg_err_set_errno (0);
       problem = strtol (args, &tail, 0);
       if (errno || (*tail && *tail != ' '))
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
       switch (problem)
 	{
diff --git a/src/engine-gpg.c b/src/engine-gpg.c
index 7cf8894a..4c7a8b2e 100644
--- a/src/engine-gpg.c
+++ b/src/engine-gpg.c
@@ -1269,7 +1269,7 @@ start (engine_gpg_t gpg)
     return gpg_error (GPG_ERR_INV_VALUE);
 
   if (!gpg->file_name && !_gpgme_get_gpg_path ())
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   if (gpg->lc_ctype)
     {
diff --git a/src/engine-gpgconf.c b/src/engine-gpgconf.c
index 8de847cd..b50b6351 100644
--- a/src/engine-gpgconf.c
+++ b/src/engine-gpgconf.c
@@ -300,7 +300,7 @@ gpgconf_config_load_cb (void *hook, char *line)
 
   /* We require at least the first 3 fields.  */
   if (fields < 2)
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   /* Find the pointer to the new component in the list.  */
   while (comp && comp->next)
@@ -426,7 +426,7 @@ gpgconf_config_load_cb2 (void *hook, char *line)
 
   /* We require at least the first 10 fields.  */
   if (fields < 10)
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   opt = calloc (1, sizeof (*opt));
   if (!opt)
diff --git a/src/engine.c b/src/engine.c
index 17d8d870..f72ce7f9 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -30,6 +30,7 @@
 #include "util.h"
 #include "sema.h"
 #include "ops.h"
+#include "debug.h"
 
 #include "engine.h"
 #include "engine-backend.h"
@@ -166,7 +167,7 @@ gpgme_engine_check_version (gpgme_protocol_t proto)
 				      info->req_version);
 
   UNLOCK (engine_info_lock);
-  return result ? 0 : gpg_error (GPG_ERR_INV_ENGINE);
+  return result ? 0 : trace_gpg_error (GPG_ERR_INV_ENGINE);
 }
 
 
@@ -359,7 +360,7 @@ _gpgme_set_engine_info (gpgme_engine_info_t info, gpgme_protocol_t proto,
     info = info->next;
 
   if (!info)
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   /* Prepare new members.  */
   if (file_name)
@@ -449,7 +450,7 @@ _gpgme_engine_new (gpgme_engine_info_t info, engine_t *r_engine)
   engine_t engine;
 
   if (!info->file_name || !info->version)
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   engine = calloc (1, sizeof *engine);
   if (!engine)
diff --git a/src/gpgconf.c b/src/gpgconf.c
index cbfd3dd4..47ef47ab 100644
--- a/src/gpgconf.c
+++ b/src/gpgconf.c
@@ -26,6 +26,7 @@
 
 #include "ops.h"
 #include "engine.h"
+#include "debug.h"
 
 #ifdef ENABLE_GPGCONF
 /* engine-gpgconf.c.  */
diff --git a/src/import.c b/src/import.c
index f599c232..d4edaba1 100644
--- a/src/import.c
+++ b/src/import.c
@@ -131,7 +131,7 @@ parse_import (char *args, gpgme_import_status_t *import_status, int problem)
     {
       /* The crypto backend does not behave.  */
       free (import);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
   args = tail;
 
@@ -196,7 +196,7 @@ parse_import_res (char *args, gpgme_import_result_t result)
   (x) = strtol (args, &tail, 0);			\
   if (errno || args == tail || *tail != ' ')		\
     /* The crypto backend does not behave.  */		\
-    return gpg_error (GPG_ERR_INV_ENGINE);		\
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);        \
   args = tail;
 
   PARSE_NEXT (result->considered);
diff --git a/src/key.c b/src/key.c
index c1d8ceb5..1094f19b 100644
--- a/src/key.c
+++ b/src/key.c
@@ -30,6 +30,7 @@
 #include "util.h"
 #include "ops.h"
 #include "sema.h"
+#include "debug.h"
 
 
 /* Protects all reference counters in keys.  All other accesses to a
diff --git a/src/op-support.c b/src/op-support.c
index 808eac87..d42a247b 100644
--- a/src/op-support.c
+++ b/src/op-support.c
@@ -31,6 +31,7 @@
 #include "context.h"
 #include "ops.h"
 #include "util.h"
+#include "debug.h"
 
 
 gpgme_error_t
@@ -199,7 +200,7 @@ _gpgme_parse_inv_recp (char *args, gpgme_invalid_key_t *key)
     {
       /* The crypto backend does not behave.  */
       free (inv_key);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
 
   switch (reason)
diff --git a/src/passphrase.c b/src/passphrase.c
index 17f14436..7e5508eb 100644
--- a/src/passphrase.c
+++ b/src/passphrase.c
@@ -32,6 +32,7 @@
 #include "context.h"
 #include "ops.h"
 #include "util.h"
+#include "debug.h"
 
 
 typedef struct
diff --git a/src/passwd.c b/src/passwd.c
index 0ed54ba6..e832026d 100644
--- a/src/passwd.c
+++ b/src/passwd.c
@@ -56,7 +56,7 @@ parse_error (char *args)
       where = args;
     }
   else
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   err = atoi (which);
 
diff --git a/src/progress.c b/src/progress.c
index 76ec47f5..a4e48f16 100644
--- a/src/progress.c
+++ b/src/progress.c
@@ -28,6 +28,7 @@
 
 #include "util.h"
 #include "context.h"
+#include "debug.h"
 
 
 gpgme_error_t
diff --git a/src/sig-notation.c b/src/sig-notation.c
index 8386378a..46efac6d 100644
--- a/src/sig-notation.c
+++ b/src/sig-notation.c
@@ -30,6 +30,7 @@
 #include "util.h"
 #include "context.h"
 #include "ops.h"
+#include "debug.h"
 
 
 /* Free the signature notation object and all associated resources.
@@ -159,13 +160,13 @@ _gpgme_parse_notation (gpgme_sig_notation_t *notationp,
 
   /* A few simple sanity checks.  */
   if (len > strlen (data))
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   /* See below for the format of a notation subpacket.  It has at
      least four octets of flags and two times two octets of length
      information.  */
   if (type == 20 && len < 4 + 2 + 2)
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   err = _gpgme_decode_percent_string (data, &decoded_data, 0, 1);
   if (err)
@@ -234,7 +235,7 @@ _gpgme_parse_notation (gpgme_sig_notation_t *notationp,
       if (4 + 2 + 2 + name_len + value_len > len)
 	{
 	  free (decoded_data);
-	  return gpg_error (GPG_ERR_INV_ENGINE);
+	  return trace_gpg_error (GPG_ERR_INV_ENGINE);
 	}
 
       name = (char *) bdata;
diff --git a/src/sign.c b/src/sign.c
index 15092049..67280e9f 100644
--- a/src/sign.c
+++ b/src/sign.c
@@ -169,14 +169,14 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     default:
       /* The backend engine is not behaving.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
 
   args++;
   if (*args != ' ')
     {
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
 
   gpg_err_set_errno (0);
@@ -185,7 +185,7 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     {
       /* The crypto backend does not behave.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
   args = tail;
 
@@ -194,7 +194,7 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     {
       /* The crypto backend does not behave.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
   args = tail;
 
@@ -205,7 +205,7 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     {
       /* The crypto backend does not behave.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
   args = tail;
 
@@ -214,7 +214,7 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     {
       /* The crypto backend does not behave.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
   args = tail;
   while (*args == ' ')
@@ -224,7 +224,7 @@ parse_sig_created (char *args, gpgme_new_signature_t *sigp)
     {
       /* The crypto backend does not behave.  */
       free (sig);
-      return gpg_error (GPG_ERR_INV_ENGINE);
+      return trace_gpg_error (GPG_ERR_INV_ENGINE);
     }
 
   tail = strchr (args, ' ');
diff --git a/src/trust-item.c b/src/trust-item.c
index 226298b4..5a0b5449 100644
--- a/src/trust-item.c
+++ b/src/trust-item.c
@@ -30,6 +30,7 @@
 #include "util.h"
 #include "ops.h"
 #include "sema.h"
+#include "debug.h"
 
 
 /* Protects all reference counters in trust items.  All other accesses
diff --git a/src/verify.c b/src/verify.c
index a61cc950..c32241ae 100644
--- a/src/verify.c
+++ b/src/verify.c
@@ -346,7 +346,7 @@ parse_new_sig (op_data_t opd, gpgme_status_code_t code, char *args)
       /* Parse the timestamp.  */
       sig->timestamp = _gpgme_parse_timestamp (end, &tail);
       if (sig->timestamp == -1 || end == tail || (*tail && *tail != ' '))
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
       end = tail;
       while (*end == ' ')
 	end++;
@@ -420,12 +420,12 @@ parse_valid_sig (gpgme_signature_t sig, char *args)
 
       sig->timestamp = _gpgme_parse_timestamp (end, &tail);
       if (sig->timestamp == -1 || end == tail || (*tail && *tail != ' '))
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
       end = tail;
 
       sig->exp_timestamp = _gpgme_parse_timestamp (end, &tail);
       if (sig->exp_timestamp == -1 || end == tail || (*tail && *tail != ' '))
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
       end = tail;
 
       while (*end == ' ')
@@ -445,7 +445,7 @@ parse_valid_sig (gpgme_signature_t sig, char *args)
 	      gpg_err_set_errno (0);
 	      sig->pubkey_algo = strtol (end, &tail, 0);
 	      if (errno || end == tail || *tail != ' ')
-		return gpg_error (GPG_ERR_INV_ENGINE);
+		return trace_gpg_error (GPG_ERR_INV_ENGINE);
 	      end = tail;
 
 	      while (*end == ' ')
@@ -458,7 +458,7 @@ parse_valid_sig (gpgme_signature_t sig, char *args)
 		  gpg_err_set_errno (0);
 		  sig->hash_algo = strtol (end, &tail, 0);
 		  if (errno || end == tail || *tail != ' ')
-		    return gpg_error (GPG_ERR_INV_ENGINE);
+		    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 		  end = tail;
 		}
 	    }
@@ -491,7 +491,7 @@ parse_notation (gpgme_signature_t sig, gpgme_status_code_t code, char *args)
       if (notation)
 	/* There is another notation name without data for the
 	   previous one.  The crypto backend misbehaves.  */
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
       err = _gpgme_sig_notation_create (&notation, NULL, 0, NULL, 0, 0);
       if (err)
@@ -544,7 +544,7 @@ parse_notation (gpgme_signature_t sig, gpgme_status_code_t code, char *args)
       if (!notation || !notation->name)
 	/* There is notation data without a previous notation
 	   name.  The crypto backend misbehaves.  */
-	return gpg_error (GPG_ERR_INV_ENGINE);
+	return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
       if (!notation->value)
 	{
@@ -569,7 +569,7 @@ parse_notation (gpgme_signature_t sig, gpgme_status_code_t code, char *args)
       notation->value_len += strlen (dest);
     }
   else
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
   return 0;
 }
 
@@ -645,7 +645,7 @@ parse_error (gpgme_signature_t sig, char *args, int set_status)
       where = args;
     }
   else
-    return gpg_error (GPG_ERR_INV_ENGINE);
+    return trace_gpg_error (GPG_ERR_INV_ENGINE);
 
   err = atoi (which);
 
@@ -708,7 +708,7 @@ _gpgme_verify_status_handler (void *priv, gpgme_status_code_t code, char *args)
     case GPGME_STATUS_VALIDSIG:
       opd->only_newsig_seen = 0;
       return sig ? parse_valid_sig (sig, args)
-	: gpg_error (GPG_ERR_INV_ENGINE);
+	: trace_gpg_error (GPG_ERR_INV_ENGINE);
 
     case GPGME_STATUS_NODATA:
       opd->only_newsig_seen = 0;
@@ -729,7 +729,7 @@ _gpgme_verify_status_handler (void *priv, gpgme_status_code_t code, char *args)
     case GPGME_STATUS_POLICY_URL:
       opd->only_newsig_seen = 0;
       return sig ? parse_notation (sig, code, args)
-	: gpg_error (GPG_ERR_INV_ENGINE);
+	: trace_gpg_error (GPG_ERR_INV_ENGINE);
 
     case GPGME_STATUS_TRUST_UNDEFINED:
     case GPGME_STATUS_TRUST_NEVER:
@@ -738,7 +738,7 @@ _gpgme_verify_status_handler (void *priv, gpgme_status_code_t code, char *args)
     case GPGME_STATUS_TRUST_ULTIMATE:
       opd->only_newsig_seen = 0;
       return sig ? parse_trust (sig, code, args)
-	: gpg_error (GPG_ERR_INV_ENGINE);
+	: trace_gpg_error (GPG_ERR_INV_ENGINE);
 
     case GPGME_STATUS_PKA_TRUST_BAD:
     case GPGME_STATUS_PKA_TRUST_GOOD:
@@ -746,7 +746,7 @@ _gpgme_verify_status_handler (void *priv, gpgme_status_code_t code, char *args)
       /* Check that we only get one of these status codes per
          signature; if not the crypto backend misbehaves.  */
       if (!sig || sig->pka_trust || sig->pka_address)
-        return gpg_error (GPG_ERR_INV_ENGINE);
+        return trace_gpg_error (GPG_ERR_INV_ENGINE);
       sig->pka_trust = code == GPGME_STATUS_PKA_TRUST_GOOD? 2 : 1;
       end = strchr (args, ' ');
       if (end)
diff --git a/src/wait-global.c b/src/wait-global.c
index f3aa399b..9a194b0d 100644
--- a/src/wait-global.c
+++ b/src/wait-global.c
@@ -34,6 +34,7 @@
 #include "wait.h"
 #include "priv-io.h"
 #include "ops.h"
+#include "debug.h"
 
 /* The global event loop is used for all asynchronous operations
    (except key listing) for which no user I/O callbacks are specified.
diff --git a/src/wait-private.c b/src/wait-private.c
index d0552cea..aab8fb7f 100644
--- a/src/wait-private.c
+++ b/src/wait-private.c
@@ -31,6 +31,7 @@
 #include "ops.h"
 #include "priv-io.h"
 #include "util.h"
+#include "debug.h"
 
 
 /* The private event loops are used for all blocking operations, and
diff --git a/src/wait-user.c b/src/wait-user.c
index 42bb3a5b..ba287617 100644
--- a/src/wait-user.c
+++ b/src/wait-user.c
@@ -29,6 +29,7 @@
 #include "priv-io.h"
 #include "wait.h"
 #include "ops.h"
+#include "debug.h"
 
 
 /* The user event loops are used for all asynchronous operations for