[[ROS 05-08 Hint from Alex Schmiedel – Use Different Command with Serial Number|👉 Next page]]
# ROS 05-07 Checking the Log and the Error that Occurred when Using catkin_make
## Preliminaries
I will check the log and the error that occurred when I used `catkin_make`.
Here I used the command `catkin_make`:
![[catkin_make_1.png]]
![[catkin_make_5.png]]
So the error said:
`/home/thomas/catkin_ws/src/rplidar_ros/sdk/src/arch/linux/net_serial.cpp: In member function ´virtual void rp::arch::net::raw_serial::cancelOperation()´:/home/thomas/catkin_ws/src/rplidar_ros/sdk/src/arch/linux/net_serial.cpp:428:12: warning: ignoring return value of ´ssize_t write(int, const void*, size_t)´, declared with attribute warn unused_result [-Wunused-result]`
`::write(_selfpipe_[1], "x", 1);
And it was when this operation occured:
`[ 28 % ] Building CXX object rplidar_ros/CMakeFiles/rplidarNote.dir/sdk/src/arch/linux/net_serial.cpp.o`
==This error looks quite so as if it was the cause of my problems==
## Working with that
I could now
- redo the `make_catkin` command, but first I'd have to check if I have to deinstall or delete something before
- search for parts of the error message online
As research is always the best way to proceed, I go with the later first.
### Checking online for parts of the error code
I first just search for most of it, just without my name:
`/home/catkin_ws/src/rplidar_ros/sdk/src/arch/linux/net_serial.cpp: In member function ´virtual void rp::arch::net::raw_serial::cancelOperation()´:/home/catkin_ws/src/rplidar_ros/sdk/src/arch/linux/net_serial.cpp:428:12: warning: ignoring return value of ´ssize_t write(int, const void*, size_t)´, declared with attribute warn unused_result [-Wunused-result]`
The result gives me some hope:
![[thn-searching-for-error-catkin_make-hope.png]]
But let's have a look first: https://bbs.archlinux.org/viewtopic.php?id=285729
No, these hopes were unjustified in this case. Should have deleted the apostrophes, though.
So I try the same input with `Jetson Nano`.
I have to try smaller samples:
I try
`warning: ignoring return value of ´ssize_t write(int, const void*, size_t)´, declared with attribute warn unused_result [-Wunused-result]`
and `Jetson Nano`
The results are more concerned with the programming language `C`.
Let's try
`Jetson Nano error ::write(_selfpipe_[1], "x", 1);`
Only works without the first three key words:
- https://github.com/Slamtec/rplidar_sdk/issues/55
- interesting, but quite far of, for me at least
Let's try less brute force, more common sense and search for:
`Jetson Nano error ROS catkin_make`
Not really fitting these findings.
---
I stop here and after having a short chat with #Schmiedel_Alex I try the hint given by him which I had in the back of my mind but did not know how to use it, yet: That [[ROS 05-08 Hint from Alex Schmiedel – Use Different Command with Serial Number|I have to add the serial number]].
---
[[ROS 05-08 Hint from Alex Schmiedel – Use Different Command with Serial Number|👉 Next page]]
# Back to:
[[ROS 05-06 Why is There Double src in the New Error Response?]]