cmake error

[mathpopo]

because:

https://bitbucket.org/eigen/eigen/get/3.2.10.tar.gz

The requested repository either does not exist or you do not have access. If you believe this repository exists and you have access, make sure you're authenticated.

so:
CMake Error at .cache/eigen/eigen-download-prefix/src/eigen-download-stamp/download-eigen-download.cmake:170 (message):
Each download failed!

error: downloading 'http://bitbucket.org/eigen/eigen/get/3.2.10.tar.gz' failed
      status_code: 1
      status_string: "Unsupported protocol"
      log:
      --- LOG BEGIN ---
        Trying 104.192.141.1:80...
Trying 2406:da00:ff00::22e9:9f55:80...

Immediate connect fail for 2406:da00:ff00::22e9:9f55: Network is
unreachable

Trying 2406:da00:ff00::22c5:2ef4:80...

Immediate connect fail for 2406:da00:ff00::22c5:2ef4: Network is
unreachable

Trying 2406:da00:ff00::22c0:3470:80...

Immediate connect fail for 2406:da00:ff00::22c0:3470: Network is
unreachable

Trying 2406:da00:ff00::3403:4be7:80...

Immediate connect fail for 2406:da00:ff00::3403:4be7: Network is
unreachable

Trying 2406:da00:ff00::6b17:d1f5:80...

Immediate connect fail for 2406:da00:ff00::6b17:d1f5: Network is
unreachable

Trying 2406:da00:ff00::22cd:e0db:80...

Immediate connect fail for 2406:da00:ff00::22cd:e0db: Network is
unreachable

Connected to bitbucket.org (104.192.141.1) port 80 (#0)

GET /eigen/eigen/get/3.2.10.tar.gz HTTP/1.1

Host: bitbucket.org

User-Agent: curl/7.77.0

Accept: /

Mark bundle as not supporting multiuse

HTTP/1.1 301 Moved Permanently

Content-Type: text/html

Date: Tue, 08 Feb 2022 07:27:39 GMT

Location: https://bitbucket.org/eigen/eigen/get/3.2.10.tar.gz

Connection: Keep-Alive

Content-Length: 0

Connection #0 to host bitbucket.org left intact

      --- LOG END ---

make[2]: *** [CMakeFiles/eigen-download.dir/build.make:99：eigen-download-prefix/src/eigen-download-stamp/eigen-download-download] 错误 1
make[1]: *** [CMakeFiles/Makefile2:83：CMakeFiles/eigen-download.dir/all] 错误 2
make: *** [Makefile:91：all] 错误 2
CMake Error at external/libigl/cmake/DownloadProject.cmake:179 (message):
Build step for eigen failed: 2
Call Stack (most recent call first):
external/libigl/cmake/LibiglDownloadExternal.cmake:14 (download_project)
external/libigl/cmake/LibiglDownloadExternal.cmake:52 (igl_download_project)
external/libigl/cmake/libigl.cmake:100 (igl_download_eigen)
cmake/FindLIBIGL.cmake:36 (include)
CMakeLists.txt:66 (find_package)

-- Configuring incomplete, errors occurred!
See also "/home/chenxin/disk1/github/eos-model-viewer/build/CMakeFiles/CMakeOutput.log".

[patrikhuber]

This is caused by the dependency, libigl, which seems to download Eigen from their old (now non-existing) Bitbucket repo.
You can either try to make libigl use a local Eigen installation of yours, or cd into external/libigl and update the libigl submodule. The latter might require some updates to the eos-model-viewer too though, igl might have changed some of their APIs in the last 3 years.