Cannot specify name and version when generating a lock file - conan

Question

I am using a simple conan file example from a repository of examples. I would like to generate a lockfile, but when I try the command, I get this error:
.../folly/basic $ conan lock create
ERROR: Specify the 'name' and the 'version'
When I try to do so, following the documentation, I still get the same error:
.../folly/basic $ conan lock create --name=libb --version=0.2
ERROR: Specify the 'name' and the 'version'
.../folly/basic $ conan lock create --name libb --version 0.2
ERROR: Specify the 'name' and the 'version'
Does anybody have any advice? I am sure it's something obvious, but I am new to conan.

Answer 1

The Conan lock create requires a conanfile.py file which is not present in your example. That example uses a simple conanfile.txt to install the project dependencies (Folly and OpenSSL).
You still can generate the lock file by installing those requirements:
$ mkdir build && cd build/
$ conan install ..
...
$ ls
conan.lock conanbuildinfo.cmake conanbuildinfo.txt conaninfo.txt graph_info.json
Also, note that you are not passing the conanfile path, as required by the command:
.../folly/basic $ conan lock create
ERROR: Specify the 'name' and the 'version'
Instead, you should pass the path where the conanfile.py is installed:
$ conan lock create conanfile.py
However, if you want to generate a lock file only for a single reference (e.g. Folly), you can directly do it by the follow command:
$ conan lock create --reference folly/2020.08.10.00# -r conancenter