---
title: "UDP-client project won't compile"
url: "https://maker.wiznet.io/forum/15725"
markdown_url: "https://maker.wiznet.io/forum/15725/md"
type: "Forum topic"
category: "MCU & Boards"
author: "whisperquiet"
created: "2025-05-09T04:03:58+09:00"
last_activity: "2025-05-12T10:16:14+09:00"
language: "en"
views: 6
replies: 4
source: "WIZnet Makers forum (https://maker.wiznet.io/forum/)"
---

# UDP-client project won't compile

## Question

Asked by whisperquiet on 2025-05-09 in MCU & Boards.

Hello everyone, apologies for the noob question. I'm pretty new to embedded systems and Ethernet protocols in general, and I'm still early in the learning process. I tried to see if anyone already asked this question, and I do see some people with similar issues, but I didn't find anyone with the same situation.

I'm using a W5500-EVB-Pico-PoE, and I'm trying to run the [example udp-client project](https://github.com/WIZnet-ioNIC/WIZnet-PICO-C/tree/main/examples/udp/udp_client)in VScode - bog standard stuff. However, my issue is that when I try to compile the project, I get the following error in the terminal:

```plaintext
ninja: error: loading ''build.ninja'': The system cannot find the file specified.
```

(I'm unfamiliar with ninja, unfortunately)

I also get these under the Problems tab:

```plaintext
cannot open source file "pico/version.h"
cannot open source file "port_common.h"
cannot open source file "wizchip_conf.h"
cannot open source file "wizchip_spi.h"
cannot open source file "loopback.h"
```

I cloned the entire WIZnet-PICO-C repository, including the library submodules. I verified that all of these header files exist in my clone, which I haven't modified, so I'm not sure why they aren't being recognized. I've successfully run non-ethernet PICO projects via VScode, so I'm pretty sure my environment is set up correctly.

I've barely touched this project at all (only changed the network info in wizchip_udp_client.c), so I'm wondering if there is some sort of configuration I missed or don't know about. Any help y''all could provide would be greatly appreciated! Please let me know if there's any further info needed to elucidate this problem!

## Replies

### Reply 1 by whisperquiet, 2025-05-09

I've tried running

```plaintext
git submodule update --init --recursive
```

and CMake: Configure, but the Ninja error persists.

As for the CMakeLists.txt file, it doesn't appear to have any paths specified in it by default. I haven't touched the file because I've been following the instructions on the example page, and they don't make mention of adding paths to CMakeLists.txt. That didn't surprise me much when I saw it initially because the headers seem to be present in the repository itself. Is this something that an experienced user would be assumed to know by default (and therefore might not be included in the instructions)?

If it is necessary to modify the CMakeLists.txt, what precisely should I add? I tried adding the following lines, but they did not fix the issue:

```plaintext
include_directories(
    ${CMAKE_SOURCE_DIR}/libraries/ioLibrary_Driver/Ethernet
    ${CMAKE_SOURCE_DIR}/libraries/ioLibrary_Driver/Application/loopback
    ${CMAKE_SOURCE_DIR}/port
)
```

### Reply 2 by Grace_Koo, 2025-05-09

Hello,

If you are building using the Pico extension in VS Code, please try performing “Clean CMake” -> “Configure CMake”.
If the same error persists, could you let us know the version of the Pico SDK and GCC you are using?

Thank you.

### Reply 3 by whisperquiet, 2025-05-09 (in reply to reply 2)

Sure thing, and thank you for your reply!

Unfortunately, that didn't seem to fix the issue. I'm using Pico SDK v2.1.1, and my compiler is arm-none-eabi-gcc v14.2.1.

I also noticed this on the VScode splash page for the Raspberry Pi Pico extension:

## Known Issues

- Custom Paths: Custom paths for Ninja, Python3, and Git are not stored in `CMakeLists.txt` like SDK and Toolchain paths. You need to build and configure projects through the extension to use these custom paths

Maybe I'm the last guy in the world to see this, but I figured it was worth mentioning since it seemed at least potentially related. Then again, if the example CMakeLists.txt is shipped as-is and not meant to be modified to include paths, I guess this wouldn't matter too much

### Reply 4 by Grace_Koo, 2025-05-12 (in reply to reply 2)

Hello,

I have checked the issue you mentioned and updated the code accordingly.
Please download the updated code from the link below.

<https://github.com/WIZnet-ioNIC/WIZnet-PICO-C>

For building, please use the following environment:

- pico-sdk: 2.0.0

- ARM GCC Toolchain: 13.2.Rel1

If you encounter the same issue again, please let me know.
Thank you.

---

Source: https://maker.wiznet.io/forum/15725