Conan issue https://github.com/conan-io/conan/issues/8788

docker_build_with_conan.io

Sending build context to Docker daemon  48.64kB
Step 1/11 : FROM python:slim
 ---> 35a59a02a22c
Step 2/11 : RUN DEBIAN_FRONTEND=noninteractive apt update
 ---> Using cache
 ---> b78c411c7238
Step 3/11 : RUN DEBIAN_FRONTEND=noninteractive apt -y install gcc cmake
 ---> Using cache
 ---> 10aae4f6a4df
Step 4/11 : RUN python3 -m pip install conan
 ---> Using cache
 ---> c98b2354f5fb
Step 5/11 : RUN conan profile new default --detect
 ---> Using cache
 ---> 7648d4472357
Step 6/11 : RUN conan profile update settings.compiler.libcxx=libstdc++11 default
 ---> Using cache
 ---> 6b89a387345a
Step 7/11 : RUN conan remote remove conan-center
 ---> Using cache
 ---> 3694c391aeac
Step 8/11 : RUN conan remote add conan-center https://conan.io
 ---> Using cache
 ---> 850c7dde5218
Step 9/11 : RUN conan remote list
 ---> Using cache
 ---> 9783cf3160d4
Step 10/11 : COPY conanfile.txt /app
 ---> Using cache
 ---> 4e9b504bbd7d
Step 11/11 : RUN conan install /app
 ---> Running in a10ff52307ff
Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++11
compiler.version=8
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

catch2/2.13.4: Not found in local cache, looking in remotes...
catch2/2.13.4: Trying with 'conan-center'...
ERROR: Unable to find 'catch2/2.13.4' in remotes
The command '/bin/sh -c conan install /app' returned a non-zero code: 1

docker_build_without_conan.io

Sending build context to Docker daemon  48.64kB
Step 1/9 : FROM python:slim
 ---> 35a59a02a22c
Step 2/9 : RUN DEBIAN_FRONTEND=noninteractive apt update
 ---> Using cache
 ---> b78c411c7238
Step 3/9 : RUN DEBIAN_FRONTEND=noninteractive apt -y install gcc cmake
 ---> Using cache
 ---> 10aae4f6a4df
Step 4/9 : RUN python3 -m pip install conan
 ---> Using cache
 ---> c98b2354f5fb
Step 5/9 : RUN conan profile new default --detect
 ---> Using cache
 ---> 7648d4472357
Step 6/9 : RUN conan profile update settings.compiler.libcxx=libstdc++11 default
 ---> Using cache
 ---> 6b89a387345a
Step 7/9 : RUN conan remote list
 ---> Running in 667c1e63f0c0
WARN: Remotes registry file missing, creating default one in /root/.conan/remotes.json
conan-center: https://conan.bintray.com [Verify SSL: True]
Removing intermediate container 667c1e63f0c0
 ---> e488b7fcf5a5
Step 8/9 : COPY conanfile.txt /app
 ---> c256fa6e4bca
Step 9/9 : RUN conan install /app
 ---> Running in fa5d4d8c7c76
Configuration:
[settings]
arch=x86_64
arch_build=x86_64
build_type=Release
compiler=gcc
compiler.libcxx=libstdc++11
compiler.version=8
os=Linux
os_build=Linux
[options]
[build_requires]
[env]

catch2/2.13.4: Not found in local cache, looking in remotes...
catch2/2.13.4: Trying with 'conan-center'...
ERROR: HTTPSConnectionPool(host='conan.bintray.com', port=443): Max retries exceeded with url: /v1/ping (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1123)')))

Unable to connect to conan-center=https://conan.bintray.com
1. Make sure the remote is reachable or,
2. Disable it by using conan remote disable,
Then try again.
The command '/bin/sh -c conan install /app' returned a non-zero code: 1

Dockerfile

# Run using docker build .
FROM python:slim

RUN DEBIAN_FRONTEND=noninteractive apt update
RUN DEBIAN_FRONTEND=noninteractive apt -y install gcc cmake
RUN python3 -m pip install conan
RUN conan profile new default --detect
RUN conan profile update settings.compiler.libcxx=libstdc++11 default

# Uncomment this, it will also not work
#RUN conan remote remove conan-center
#RUN conan remote add conan-center https://conan.io
# Also fails with
#RUN conan remote add conan-center https://conan.io/center

RUN conan remote list
COPY conanfile.txt /app
RUN conan install /app

gistfile1.txt

[requires]
catch2/2.13.4

[generators]
cmake