conda create --name darknet python=3.7
conda activate darknet
conda install -c menpo opencv 
Hope it helps!
PCsi3:~/darknet$ make

gcc -Iinclude/ -Isrc/ -Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-errors -fPIC -Ofast -c ./src/gemm.c -o obj/gemm.o

make: gcc: Command not found

Makefile:89: recipe for target 'obj/gemm.o' failed

make: *** [obj/gemm.o] Error 127 

I am using Ubuntu 18.04 and I have the above make error!

help please
lol ..... OKAY ... I fixed it. I had to install OpenCV in the darknet folder with the syntax

 sudo apt install libopencv-dev
Afterwards, I ran the make command again and ./darknet compiled successfully
Hopefully, this helps someone. c

CHEERS!!!
This works for me. Thank you so much!!!
          
$ make

gcc -Iinclude/ -Isrc/ -Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-erro                                 rs -fPIC -Ofast -c ./src/deconvolutional_layer.c -o obj/deconvolutional_layer.o

./src/deconvolutional_layer.c:1:0: warning: -fPIC ignored for target (all code i                                 s position independent)

#include "deconvolutional_layer.h"

In file included from ./src/cuda.h:4:0,

from ./src/deconvolutional_layer.h:4,

from ./src/deconvolutional_layer.c:1:

include/darknet.h:780:11: error: unknown type name 'clock_t'

float sec(clock_t clocks);

compilation terminated due to -Wfatal-errors.

make: *** [obj/deconvolutional_layer.o] Error 1
          
I resolved it using following steps:
Installed opencv using sudo apt install libopencv-dev
Opened a new terminal (make sure that you are using version as installed in the 1st step using following command):

python -c "import cv2; print(cv2.__version__);

(In my case, bashrc was setting up env vars and another installation of opencv was active and I had to comment out relevant lines in bashrc)
make after setting OPENCV=1 in Makefile

Well not much of use, just got 2 FPS :(
Versions (other versions might also work):

Opencv: 4.2.0

No CUDA/CUDNN in use
Thank you.
Looks like you're using Darknet on Windows.
The current make file is based on linux folder structures. That's why its not able to find the src files properly.
If you want to use in Windows OS, try https://github.com/AlexeyAB/darknet
I git cloned that but after using the mingw32-make command, the following error occured

process_begin: CreateProcess(NULL, uname, ...) failed. mkdir -p ./obj/ process_begin: CreateProcess(NULL, mkdir -p ./obj/, ...) failed. make (e=2): The system cannot find the file specified. Makefile:188: recipe for target 'obj/' failed mingw32-make: *** [obj/] Error 2
          
I understand the problem, for downloading the program darknet using MAKE , the website https://pjreddie.com/darknet/install/ itself mentions about 2 programs, open cv and cuda. please download both of them and try again.
For OpenCV - sudo apt install libopencv-dev

For CUDA visit this website - https://developer.nvidia.com/cuda-downloads
Thank you
          
Same! This is the error:
$ make mkdir -p ./obj/ mkdir -p backup chmod +x *.sh g++ -std=c++11 -std=c++11 -Iinclude/ -I3rdparty/stb/include -Wall -Wfatal-errors -Wno-unused-result -Wno-unknown-pragmas -fPIC -Ofast -c ./src/image_opencv.cpp -o obj/image_opencv.o process_begin: CreateProcess(NULL, g++ -std=c++11 -std=c++11 -Iinclude/ -I3rdpar ty/stb/include -Wall -Wfatal-errors -Wno-unused-result -Wno-unknown-pragmas -fPI C -Ofast -c ./src/image_opencv.cpp -o obj/image_opencv.o, ...) failed. make (e=2): Impossibile trovare il file specificato. make: *** [Makefile:182: obj/image_opencv.o] Error 2
Have you solve it?

I need help, please
          
gcc -Iinclude/ -Isrc/ -DOPENCV pkg-config --cflags opencv -DGPU -I/usr/local/cuda/include/ -Wall -Wno-unused-result -Wno-unknown-pragmas -Wfatal-errors -fPIC -Ofast -DOPENCV -DGPU -c ./src/gemm.c -o obj/gemm.o

In file included from ./src/utils.h:5,

from ./src/gemm.c:2:

include/darknet.h:25:14: fatal error: opencv2/highgui/highgui_c.h: No such file or directory

25 |     #include "opencv2/highgui/highgui_c.h"

|              ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

compilation terminated.

make: *** [Makefile:108: obj/gemm.o] Error 1
I have installed opencv using coda and apt-get

Added opencv.pc path to PKG_CONFIG_PATH

still getting error
Any suggestion