At least for the two common Unixly DSO loading methods, include the

system error in the error text.

crypto/dso/dso_dl.c

@@ -130,7 +130,8 @@ static int dl_load(DSO *dso)
 	if(ptr == NULL)
 		{
 		DSOerr(DSO_F_DL_LOAD,DSO_R_LOAD_FAILED);
-		ERR_add_error_data(3, "filename(", filename, ")");
+		ERR_add_error_data(4, "filename(", filename, "): ",
+			strerror(errno));
 		goto err;
 		}
 	if(!sk_push(dso->meth_data, (char *)ptr))
@@ -199,7 +200,8 @@ static void *dl_bind_var(DSO *dso, const char *symname)
 	if (shl_findsym(&ptr, symname, TYPE_UNDEFINED, &sym) < 0)
 		{
 		DSOerr(DSO_F_DL_BIND_VAR,DSO_R_SYM_FAILURE);
-		ERR_add_error_data(3, "symname(", symname, ")");
+		ERR_add_error_data(4, "symname(", symname, "): ",
+			strerror(errno));
 		return(NULL);
 		}
 	return(sym);
@@ -229,7 +231,8 @@ static DSO_FUNC_TYPE dl_bind_func(DSO *dso, const char *symname)
 	if (shl_findsym(&ptr, symname, TYPE_UNDEFINED, &sym) < 0)
 		{
 		DSOerr(DSO_F_DL_BIND_FUNC,DSO_R_SYM_FAILURE);
-		ERR_add_error_data(3, "symname(", symname, ")");
+		ERR_add_error_data(4, "symname(", symname, "): ",
+			strerror(errno));
 		return(NULL);
 		}
 	return((DSO_FUNC_TYPE)sym);

crypto/dso/dso_dlfcn.c

@@ -147,7 +147,7 @@ static int dlfcn_load(DSO *dso)
 	if(ptr == NULL)
 		{
 		DSOerr(DSO_F_DLFCN_LOAD,DSO_R_LOAD_FAILED);
-		ERR_add_error_data(3, "filename(", filename, ")");
+		ERR_add_error_data(4, "filename(", filename, "): ", dlerror());
 		goto err;
 		}
 	if(!sk_push(dso->meth_data, (char *)ptr))
@@ -215,7 +215,7 @@ static void *dlfcn_bind_var(DSO *dso, const char *symname)
 	if(sym == NULL)
 		{
 		DSOerr(DSO_F_DLFCN_BIND_VAR,DSO_R_SYM_FAILURE);
-		ERR_add_error_data(3, "symname(", symname, ")");
+		ERR_add_error_data(4, "symname(", symname, "): ", dlerror());
 		return(NULL);
 		}
 	return(sym);
@@ -246,7 +246,7 @@ static DSO_FUNC_TYPE dlfcn_bind_func(DSO *dso, const char *symname)
 	if(sym == NULL)
 		{
 		DSOerr(DSO_F_DLFCN_BIND_FUNC,DSO_R_SYM_FAILURE);
-		ERR_add_error_data(3, "symname(", symname, ")");
+		ERR_add_error_data(4, "symname(", symname, "): ", dlerror());
 		return(NULL);
 		}
 	return(sym);