# CMake error: unable to read CMakeFiles.o

**URL:** https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375
**Category:** Usage
**Created:** [June 21, 2023, 9:48am UTC](https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375 "2023-06-21T09:48:58Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![XanderTest-OK](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/x/db5fbb/32.png) [@XanderTest-OK](https://discourse.cmake.org/u/XanderTest-OK)
#### Post date: [June 21, 2023, 9:48am UTC](https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375/1 "2023-06-21T09:48:58Z")

</div>

I am attempting to use OpenCV in Embarcadero C++ Builder 10.3 for the 64-bit platform. I use the RAD Studio command prompt and execute the following command to generate the MakeFiles:

> cmake -DCMAKE\_C\_COMPILER=bcc64.exe -DCMAKE\_CXX\_COMPILER=bcc64.exe -DCMAKE\_CXX\_FLAGS=“-Wno-c++11-narrowing” -G “Borland Makefiles” -DCMAKE\_BUILD\_TYPE=Debug -DBUILD\_PERF\_TESTS=OFF -DWITH\_WEBP=OFF -DWITH\_OPENEXR=OFF -DWITH\_TIFF=OFF -DBUILD\_TIFF=OFF -DBUILD\_TESTS=OFF -DWITH\_JASPER=OFF -DBUILD\_SHARED\_LIBS=OFF -DBUILD\_PROTOBUF=OFF -DBUILD\_opencv\_dnn=OFF -DBUILD\_IPP=OFF -DWITH\_IPP=OFF -DWITH\_ADE=OFF -DBUILD\_opencv\_apps=OFF C:\openCV\opencv-4.7.0

After successfully creating the MakeFiles, I proceeded to run the ‘make install’ command. However, during the linking process of ‘opencv\_core.lib’, I encountered the following error:

> Error: unable to read ‘CMakeFiles.o’
> 
> \*\* error 1 \*\* deleting lib\opencv\_core470.lib
> 
> \*\* error 1 \*\* deleting modules\core\CMakeFiles\opencv\_core.dir\all
> 
> \*\* error 1 \*\* deleting all

It is important to note that I do not encounter this error when using the 32-bit compiler, so I am unsure why it is attempting to read ‘CMakeFiles.o’. If anyone has any insights or suggestions on how to resolve this issue, I would greatly appreciate it.

---

<div class="post-metadata">

### Author: ![ben.boeckel](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [June 25, 2023, 7:44pm UTC](https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375/2 "2023-06-25T19:44:08Z")

</div>

If you run with `make VERBOSE=1`, the failing command should be printed. Can that be provided?

---

<div class="post-metadata">

### Author: ![XanderTest-OK](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/x/db5fbb/32.png) [@XanderTest-OK](https://discourse.cmake.org/u/XanderTest-OK)
#### Post date: [June 28, 2023, 7:48am UTC](https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375/3 "2023-06-28T07:48:04Z")

</div>

> [@ben.boeckel](#):
>
> make VERBOSE=1

When running that command I get the following error list:

> [16%] Linking CXX static library …..\lib\opencv\_core470d.lib  
> TLIB64 7.0 Copyright (c) 1987-2019 Embarcadero Technologies, Inc.  
> /p2048 /a “…..\lib\opencv\_core470d.lib” @CMakeFiles\opencv\_core.dir\objects1.rsp  
> CMakeFiles/opencv\_core.dir/src/algorithm.cpp.obj CMakeFiles/opencv\_core.dir/src/alloc.cpp.obj CMakeFiles/opencv\_core.dir/src/arithm.cpp.obj CMakeFiles/opencv\_core.dir/src/arithm.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/array.cpp.obj CMakeFiles/opencv\_core.dir/src/async.cpp.obj CMakeFiles/opencv\_core.dir/src/batch\_distance.cpp.obj CMakeFiles/opencv\_core.dir/src/bindings\_utils.cpp.obj CMakeFiles/opencv\_core.dir/src/buffer\_area.cpp.obj CMakeFiles/opencv\_core.dir/src/channels.cpp.obj CMakeFiles/opencv\_core.dir/src/check.cpp.obj CMakeFiles/opencv\_core.dir/src/command\_line\_parser.cpp.obj CMakeFiles/opencv\_core.dir/src/conjugate\_gradient.cpp.obj CMakeFiles/opencv\_core.dir/src/convert.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/convert\_c.cpp.obj CMakeFiles/opencv\_core.dir/src/convert\_scale.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/copy.cpp.obj CMakeFiles/opencv\_core.dir/src/count\_non\_zero.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/cuda\_gpu\_mat.cpp.obj CMakeFiles/opencv\_core.dir/src/cuda\_gpu\_mat\_nd.cpp.obj CMakeFiles/opencv\_core.dir/src/cuda\_host\_mem.cpp.obj CMakeFiles/opencv\_core.dir/src/cuda\_info.cpp.obj CMakeFiles/opencv\_core.dir/src/cuda\_stream.cpp.obj CMakeFiles/opencv\_core.dir/src/datastructs.cpp.obj CMakeFiles/opencv\_core.dir/src/directx.cpp.obj CMakeFiles/opencv\_core.dir/src/downhill\_simplex.cpp.obj CMakeFiles/opencv\_core.dir/src/dxt.cpp.obj CMakeFiles/opencv\_core.dir/src/gl\_core\_3\_1.cpp.obj CMakeFiles/opencv\_core.dir/src/glob.cpp.obj CMakeFiles/opencv\_core.dir/src/hal\_internal.cpp.obj CMakeFiles/opencv\_core.dir/src/kmeanWarning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘b’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘b’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘b’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘c’ ignored  
> Warning: duplicate file ‘CMakeFiles’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: duplicate file ‘pencv\_core’ in list, not added!  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: duplicate file ‘rc’ in list, not added!  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘g’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘g’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘h’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘k’ ignored  
> s.cpp.obj CMakeFiles/opencv\_core.dir/src/lapack.cpp.obj CMakeFiles/opencv\_core.dir/src/lda.cpp.obj CMakeFiles/opencv\_core.dir/src/logger.cpp.obj CMakeFiles/opencv\_core.dir/src/lpsolver.cpp.obj CMakeFiles/opencv\_core.dir/src/lut.cpp.obj CMakeFiles/opencv\_core.dir/src/mathfuncs.cpp.obj CMakeFiles/opencv\_core.dir/src/mathfuncs\_core.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/matmul.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_c.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_decomp.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_expressions.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_iterator.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_operations.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_sparse.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_transform.cpp.obj CMakeFiles/opencv\_core.dir/src/matrix\_wrap.cpp.obj CMakeFiles/opencv\_core.dir/src/mean.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/merge.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/minmax.cpp.obj CMakeFiles/opencv\_core.dir/src/norm.cpp.obj CMakeFiles/opencv\_core.dir/src/ocl.cpp.obj CMakeFiles/opencv\_core.dir/src/opencl/runtime/opencl\_clblas.cpp.obj CMakeFiles/opencv\_core.dir/src/opencl/runtime/opencl\_clfft.cpp.obj CMakeFiles/opencv\_core.dir/src/opencl/runtime/opencl\_core.cpp.obj CMakeFiles/opencv\_core.dir/src/opengl.cpp.obj CMakeFiles/opencv\_core.dir/src/out.cpp.obj CMakeFiles/opencv\_core.dir/src/ovx.cpp.obj CMakeFiles/opencv\_core.dir/src/parallel.cpp.obj CMakeFiles/opencv\_core.dir/src/parallel/parallel.cpp.obj CMakeFilesWarning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘m’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘n’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: invalid page size value ignored  
> /opencv\_core.dir/src/parallel/parallel\_openmp.cpp.obj CMakeFiles/opencv\_core.dir/src/parallel/parallel\_tbb.cpp.obj CMakeFiles/opencv\_core.dir/src/parallel\_impl.cpp.obj CMakeFiles/opencv\_core.dir/src/pca.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence\_base64\_encoding.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence\_json.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence\_types.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence\_xml.cpp.obj CMakeFiles/opencv\_core.dir/src/persistence\_yml.cpp.obj CMakeFiles/opencv\_core.dir/src/rand.cpp.obj CMakeFiles/opencv\_core.dir/src/softfloat.cpp.obj CMakeFiles/opencv\_core.dir/src/split.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/stat.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/stat\_c.cpp.obj CMakeFiles/opencv\_core.dir/src/stl.cpp.obj CMakeFiles/opencv\_core.dir/src/sum.dispatch.cpp.obj CMakeFiles/opencv\_core.dir/src/system.cpp.obj CMakeFiles/opencv\_core.dir/src/tables.cpp.obj CMakeFiles/opencv\_core.dir/src/trace.cpp.obj CMakeFiles/opencv\_core.dir/src/types.cpp.obj CMakeFiles/opencv\_core.dir/src/umatrix.cpp.obj CMakeFiles/opencv\_core.dir/src/utils/datafile.cpp.obj CMakeFiles/opencv\_core.dir/src/utils/filesystem.cpp.obj CMakeFiles/opencv\_core.dir/src/utils/logtagconfigparser.cpp.obj CMakeFiles/opencv\_core.dir/src/utils/logtagmanager.cpp.obj CMakeFiles/opencv\_core.dir/src/utils/samples.cpp.obj CMakeFiles/opencv\_core.dir/src/va\_intel.cpp.obj CMakeFiles/opencv\_core.dir/opencl\_kernels\_core.cpp.obj  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: invalid page size value ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘t’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘t’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘t’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘f’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘s’ ignored  
> Warning: unknown command line switch ‘v’ ignored  
> Warning: unknown command line switch ‘o’ ignored  
> Warning: unknown command line switch ‘o’ ignored
> 
> Error: unable to read ‘CMakeFiles.o’
> 
> \*\* error 1 \*\* deleting lib\opencv\_core470d.lib
> 
> \*\* error 1 \*\* deleting modules\core\CMakeFiles\opencv\_core.dir\all
> 
> \*\* error 1 \*\* deleting all

Is that what you wanted me to provide?

---

<div class="post-metadata">

### Author: ![ben.boeckel](https://discourse.cmake.org/letter_avatar_proxy/v4/letter/b/ea5d25/32.png) [@ben.boeckel](https://discourse.cmake.org/u/ben.boeckel)
#### Post date: [July 1, 2023, 9:05pm UTC](https://discourse.cmake.org/t/cmake-error-unable-to-read-cmakefiles-o/8375/4 "2023-07-01T21:05:17Z")

</div>

Yes, thanks. It looks like the `/` in the paths are being interpreted as switches:

```auto
CMakeFiles/opencv_core.dir/src/algorithm.cpp.obj

```

seems to align with:

```auto
Warning: unknown command line switch ‘o’ ignored
Warning: unknown command line switch ‘s’ ignored
Warning: duplicate file ‘CMakeFiles’ in list, not added!

```

I suspect that CMake needs to learn that this compiler wants `\` separators on Windows.