Include - fatal error - no such file or directory (Eigen/Dense)

[krzysz28tof]

Setup

• VS Code
• Makefile tools (VS Code)
• Arch Linux
• Eigen (c++ library, installed via pacman)
• /usr/include/eigen3/Eigen (location of Eigen library)
• ln -s /usr/include/eigen3/Eigen Eigen (made a symbolic link in /usr/include folder)

Problem

• running make in the terminal works
• running inside VS Code with Makefile tools gives error, it cannot find my library (Eigen)
• removing IntelliSense doesn't solve the issue, running with Makefile still gives the same error

Error message

main.cpp:2:10: fatal error: Eigen/Dense: No such file or directory
2 | #include <Eigen/Dense>

[Yingzi1234]

@krzysz28tof Thank you for your github issue! To better reproduce your problem, could you provide us with a video of your reproduction project and reproduction steps? This will help us greatly in our investigation of your problem.

[krzysz28tof]

Steps

• install Eigen c++ library (via pacman on archlinux, installed into /usr/include/eigen3/Eigen)
• install VS Code
• download simple C/C++ extension (VS Code)
• download Makefile tools extension (VS Code)
• create Makefile (target "all", just compile main.cpp)
• configure Makefile tools using the Makfile tools icon in VS Code
• meaning set makefile path, build target, launch target

Problem description

• in terminal running make works
• in VS Code Makefile tools doesn't want to compile the code, saying it doesn't know the "Eigen" library

[krzysz28tof]

Screencast.From.2024-09-30.11-00-40.webm

[Yingzi1234]

@krzysz28tof Thanks for the reply, sorry I wanted to ask please do you have a dense folder under your Eigen folder?

[krzysz28tof]

@Yingzi1234 Yes

[Yingzi1234]

Hi @krzysz28tof @gcampbell-msft We can reproduce this issue, you can get the details below. This issue can be reproduced on Windows, Linux, Mac platforms. Thank you!

ENV:
VSCode: 1.94.2
Makefile tools: 0.12.8(pre-release)
C/C++: 1.22.9

Repro steps:

1. Install Eigen c++ library
2. Download and open this folder Test2.zip with VSCode
3. Click F1 and run command "Makefile: configure"
4. Open terminal window and run g++ -o main main.cpp

Actual result:
The error will be displayed:

main.cpp:2:10: fatal error: Eigen/Dense: No such file or directory
2 | #include <Eigen/Dense>

[gcampbell-msft]

@krzysz28tof @Yingzi1234 Apologies for the delay, we've added this to our backlog, thanks!

[gcampbell-msft]

@Yingzi1234 @krzysz28tof I just downloaded the repro and I was able to get it to work on my machine. One thing that I had to do was once I got the include directory correct such that it worked on the command-line, I had to run make clean and then reload the VS Code window, and then the Intellisense worked as expected and the running of Makefile configure and Makefile build worked as expected.

Also, my include directory after installing with sudo apt install libeigen3-dev was not /usr/include/eigen3/Eigen, it was /usr/include/eigen3.

Do any of these suggestions make your case work, like it did on my machine?