Hi, Sergey,

also added err_details to processing of PROFILE_ERRIO as discussed:

diff --git a/src/lib_misc.c b/src/lib_misc.c
index 79cfaf7b..83669268 100644
--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -267,6 +267,7 @@ static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt,
 
     status = set_output_path(path, opt);
     if (status != PROFILE_SUCCESS) {
+      *err_details = path;
       lj_mem_free(ctx->g, ctx, sizeof(*ctx));
       return status;
     }
@@ -293,7 +294,7 @@ static int sysprof_error(lua_State *L, int status, const char *err_details)
       lua_pushinteger(L, EINVAL);
       return 3;
     case PROFILE_ERRIO:
-      return luaL_fileresult(L, 0, NULL);
+      return luaL_fileresult(L, 0, err_details);
 #endif
     default:
       lj_assertL(0, "bad sysprof error %d", status);
diff --git a/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua b/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
index 32ce75bc..9fa779a7 100644
--- a/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
+++ b/test/tarantool-tests/profilers/misclib-sysprof-lapi.test.lua
@@ -128,8 +128,9 @@ test:ok(type(errno) == "number", "errno with not running")
 
 -- Bad path.
 res, err, errno = misc.sysprof.start({ mode = "C", path = BAD_PATH })
-test:ok(res == nil and err:match("No such file or directory"),
-        "result status and error with bad path")
+test:ok(res == nil, "result status with bad path")
+local error_msg = ("%s: No such file or directory"):format(BAD_PATH)
+test:ok(err == error_msg, "error with bad path")
 test:ok(type(errno) == "number", "errno with bad path")
 
 -- Path is not a string.

On 05.03.2025 10:55, Sergey Kaplun wrote:
Hi, Sergey!
Thanks for the fixes!
LGTM, after fixing 3 minor nits below.

On 24.02.25, Sergey Bronnikov wrote:
Hi, Sergey,

changes applied and force-pushed.

Sergey

On 24.02.2025 15:46, Sergey Kaplun via Tarantool-patches wrote:
Hi, Sergey!
Thanks for the fixes!
LGTM, after the final polishing, please consider my comments below.

On 20.02.25, Sergey Bronnikov wrote:
<snipped>

---
  src/lib_misc.c                                | 77 ++++++++++++-------
  src/lj_errmsg.h                               |  5 ++
  .../profilers/misclib-sysprof-lapi.test.lua   | 68 ++++++++++++++--
  3 files changed, 114 insertions(+), 36 deletions(-)

diff --git a/src/lib_misc.c b/src/lib_misc.c
index 5b7a4b62..1fd06dd1 100644
--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -14,6 +14,7 @@
  
  #include "lj_obj.h"
  #include "lj_str.h"
+#include "lj_strfmt.h"
Please add the corresponding include (after lj_str.h) in <src/Makefile.dep.original> to
avoid conflicts when we use this file (for crossbuilds or whatever).
There is no corresponding update on the branch.


        
<snipped>

-static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt, int idx) {
-  GCtab *options = lj_lib_checktab(L, idx);
+static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt,
+	                      const char **err_details) {
Nit: Please, replace every 8 spaces with one tab.
Fixed:

--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -180,7 +180,7 @@ static int set_output_path(const char *path, struct 
luam_Sysprof_Options *opt) {
  }

  static int parse_sysprof_opts(lua_State *L, struct 
luam_Sysprof_Options *opt,
-                             const char **err_details) {
+                             const char **err_details) {
Thanks!
Please apply the following patch. It fixes all patchset-related places.

===================================================================
diff --git a/src/lib_misc.c b/src/lib_misc.c
index 94ec6564..79cfaf7b 100644
--- a/src/lib_misc.c
+++ b/src/lib_misc.c
@@ -199,13 +199,13 @@ static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt,
     cTValue *mode_opt = lj_tab_getstr(options, lj_str_newlit(L, "mode"));
     if (mode_opt) {
       if (!tvisstr(mode_opt)) {
-        *err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
-        return PROFILE_ERRUSE;
+	*err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
+	return PROFILE_ERRUSE;
       }
       mode = strVdata(mode_opt);
       if (strlen(mode) == 0 || mode[1] != '\0') {
-        *err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
-        return PROFILE_ERRUSE;
+	*err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
+	return PROFILE_ERRUSE;
       }
     }
 
@@ -223,8 +223,8 @@ static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt,
         opt->mode = LUAM_SYSPROF_CALLGRAPH;
         break;
       default:
-        *err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
-        return PROFILE_ERRUSE;
+	*err_details = err2msg(LJ_ERR_PROF_DETAILS_BADMODE);
+	return PROFILE_ERRUSE;
     }
   }
 
@@ -235,8 +235,8 @@ static int parse_sysprof_opts(lua_State *L, struct luam_Sysprof_Options *opt,
     if (interval && tvisnumber(interval)) {
       int32_t signed_interval = numberVint(interval);
       if (signed_interval < 1) {
-        *err_details = err2msg(LJ_ERR_PROF_DETAILS_BADINTERVAL);
-        return PROFILE_ERRUSE;
+	*err_details = err2msg(LJ_ERR_PROF_DETAILS_BADINTERVAL);
+	return PROFILE_ERRUSE;
       }
       opt->interval = signed_interval;
     }
@@ -281,9 +281,9 @@ static int sysprof_error(lua_State *L, int status, const char *err_details)
     case PROFILE_ERRUSE:
       lua_pushnil(L);
       if (err_details)
-        lj_strfmt_pushf(L, "%s: %s", err2msg(LJ_ERR_PROF_MISUSE), err_details);
+	lj_strfmt_pushf(L, "%s: %s", err2msg(LJ_ERR_PROF_MISUSE), err_details);
       else
-        lua_pushstring(L, err2msg(LJ_ERR_PROF_MISUSE));
+	lua_pushstring(L, err2msg(LJ_ERR_PROF_MISUSE));
       lua_pushinteger(L, EINVAL);
       return 3;
 #if LJ_HASSYSPROF
===================================================================

    int n = (int)(L->top - L->base);
<snipped>

+test:is(res, false, "res with not a table")
+test:ok(err:match("table expected, got string"),
+        "error with not a table")
+test:is(errno, nil, "errno with not a table")
There is no need to check or declare the `errno` variable. It's always
`nil` for the case when the error is raised.
The check is cheap, why not?
This is kind of misleading, plus this is a dead check. It is __always__
`nil`, or we will get an error in the first test and the second test.
Since we are not testing `pcall()` implementation here, let's just drop
it (it is even cheaper :)).

<snipped>