feat(loader): Added hints for some serial port issues when rising por…

…t error

Closes espressif/esp-idf#12366

esptool/loader.py

@@ -302,9 +302,37 @@ def __init__(self, port=DEFAULT_PORT, baud=ESP_ROM_BAUD, trace_enabled=False):
             try:
                 self._port = serial.serial_for_url(port)
             except serial.serialutil.SerialException as e:
+                port_issues = [
+                    [  # does not exist error
+                        re.compile(r"Errno 2|FileNotFoundError", re.IGNORECASE),
+                        "Check if the port is correct and ESP connected",
+                    ],
+                    [  # busy port error
+                        re.compile(r"Access is denied", re.IGNORECASE),
+                        "Check if the port is not used by another task",
+                    ],
+                ]
+                if sys.platform.startswith("linux"):
+                    port_issues.append(
+                        [  # permission denied error
+                            re.compile(r"Permission denied", re.IGNORECASE),
+                            (
+                                "Try to add user into dialout group: "
+                                "sudo usermod -a -G dialout $USER"
+                            ),
+                        ],
+                    )
+
+                hint_msg = ""
+                for port_issue in port_issues:
+                    if port_issue[0].search(str(e)):
+                        hint_msg = f"\nHint: {port_issue[1]}\n"
+                        break
+
                 raise FatalError(
                     f"Could not open {port}, the port is busy or doesn't exist."
                     f"\n({e})\n"
+                    f"{hint_msg}"
                 )
         else:
             self._port = port