Note how to resolve possible error

Author: Lealem Amedie

ide/STM32CUBE/README.md

@@ -1,12 +1,12 @@
-# wolfSSH for STM32 Cube IDE 
+# wolfSSH for STM32 Cube IDE
 
 The wolfSSH Cube Pack can be found [here](https://www.wolfssl.com/files/ide/I-CUBE-wolfSSH.pack) and is dependent on the `wolfCrypt` library.
 
 1. The first step is to set up the wolfCrypt library in your ST project following the guide here [https://github.com/wolfSSL/wolfssl/blob/master/IDE/STM32Cube/README.md](https://github.com/wolfSSL/wolfssl/blob/master/IDE/STM32Cube/README.md). To run the wolfSSH unit tests, name the entry function `wolfSSHTest` instead of `wolfCryptDemo`.
 
 2. Then install the wolfSSH Cube Pack in the same manner as the wolfSSL pack with CUBEMX.
 
-3. Open the project `.ioc` file and click the `Software Packs` drop down menu and then `Select Components`. Expand the `wolfSSH` pack and check all the components. 
+3. Open the project `.ioc` file and click the `Software Packs` drop down menu and then `Select Components`. Expand the `wolfSSH` pack and check all the components.
 
 4. In the `Software Packs` configuration category of the `.ioc` file, click on the wolfSSH pack and enable the library by checking the box.
 
@@ -20,3 +20,11 @@ The wolfSSH Cube Pack can be found [here](https://www.wolfssl.com/files/ide/I-CU
 - Make sure to make [these changes](https://github.com/wolfSSL/wolfssl/tree/master/IDE/STM32Cube#stm32-printf) to redirect the printf's to the UART.
 
 - If looking to enable filesystem support (required for SFTP), the pack assumes the user has defined their own filesystem in `wolfssh/myFilesystem.h`. That file will originally contain a dummy filesystem. If going the FATFS route, make sure to replace `#define WOLFSSH_USER_FILESYSTEM` with `#define WOLFSSH_FATFS` in the `wolfSSL.I-CUBE-wolfSSH_conf.h` header file. The wolfSSL Cube Pack also defaults to disabling filesystem support so make sure to remove `#define NO_FILESYSTEM` from `wolfSSL.I-CUBE-wolfSSL_conf.h`.
+
+- If building with LwIP and you encounter the error `multiple definition of 'errno'` in `Middlewares/Third_Party/LwIP/system/OS/sys_arch.c`, modify the file as shown below.
+```
+#if defined(LWIP_SOCKET_SET_ERRNO) && defined(LWIP_PROVIDE_ERRNO)
+- int errno;
++ extern int errno;
+#endif
+```