Cannot resolve Python version

• I am on the latest Poetry version.
• I have searched the issues of this repo and believe that this is not a duplicate.
• If an exception occurs when executing a command, I executed it again in debug mode (-vvv option).

Config:

[tool.poetry]
name = "my-package"
version = "0.1.0"
authors = ["oooo"]

[tool.poetry.dependencies]
poetry = {git='https://github.com/sdispater/poetry.git', branch='master'}

Output of poetry lock:

Updating dependencies
Resolving dependencies... (4.1s)
                                                                            
[SolverProblemError]                                         
The current project must support the following Python versions: *         
Because no versions of poetry match !=0.12.10                             
 and poetry (0.12.10) requires Python ~2.7 || ^3.4, poetry is forbidden.  
So, because my-package depends on poetry (*), version solving failed.     
                                                                            
lock

Output of poetry debug:info:

Poetry
======

 * Version: 0.12.10
 * Python:  3.5.2


Virtualenv
==========

 * Python:         3.5.2
 * Implementation: CPython
 * Path:           NA


System
======

 * Platform: linux
 * OS:       posix
 * Python:   /usr

Output of lock with -vvv:

Virtualenv my-package-py3.5 already exists.
Using virtualenv: /home/gram/.cache/pypoetry/virtualenvs/my-package-py3.5
Updating dependencies
Resolving dependencies...
   1: fact: my-package is 0.1.0
   1: derived: my-package
   1: fact: my-package depends on poetry (*)
   1: selecting my-package (0.1.0)
   1: derived: poetry (*)
   1: fact: poetry (0.12.10) requires Python ~2.7 || ^3.4
   1: derived: not poetry (0.12.10)
   1: fact: no versions of poetry match !=0.12.10
   1: conflict: no versions of poetry match !=0.12.10
   1: ! poetry (!=0.12.10) is partially satisfied by not poetry (0.12.10)
   1: ! which is caused by "poetry (0.12.10) requires Python ~2.7 || ^3.4"
   1: ! thus: poetry is forbidden
   1: ! poetry (*) is satisfied by poetry (*)
   1: ! which is caused by "my-package depends on poetry (*)"
   1: ! thus: version solving failed
   1: Version solving took 3.994 seconds.
   1: Tried 1 solutions.
                                                                            
[SolverProblemError]                                         
The current project must support the following Python versions: *         
Because no versions of poetry match !=0.12.10                             
 and poetry (0.12.10) requires Python ~2.7 || ^3.4, poetry is forbidden.  
So, because my-package depends on poetry (*), version solving failed.     
                                                                            
Exception trace:
 /home/gram/.local/lib/python3.5/site-packages/cleo/application.py in run() at line 94
   status_code = self.do_run(input_, output_)
 /home/gram/.local/lib/python3.5/site-packages/poetry/console/application.py in do_run() at line 88
   return super(Application, self).do_run(i, o)
 /home/gram/.local/lib/python3.5/site-packages/cleo/application.py in do_run() at line 197
   status_code = command.run(input_, output_)
 /home/gram/.local/lib/python3.5/site-packages/poetry/console/commands/command.py in run() at line 77
   return super(BaseCommand, self).run(i, o)
 /home/gram/.local/lib/python3.5/site-packages/cleo/commands/base_command.py in run() at line 146
   status_code = self.execute(input_, output_)
 /home/gram/.local/lib/python3.5/site-packages/cleo/commands/command.py in execute() at line 107
   return self.handle()
 /home/gram/.local/lib/python3.5/site-packages/poetry/console/commands/lock.py in handle() at line 33
   return installer.run()
 /home/gram/.local/lib/python3.5/site-packages/poetry/installation/installer.py in run() at line 76
   self._do_install(local_repo)
 /home/gram/.local/lib/python3.5/site-packages/poetry/installation/installer.py in _do_install() at line 158
   ops = solver.solve(use_latest=self._whitelist)
 /home/gram/.local/lib/python3.5/site-packages/poetry/puzzle/solver.py in solve() at line 38
   packages, depths = self._solve(use_latest=use_latest)
 /home/gram/.local/lib/python3.5/site-packages/poetry/puzzle/solver.py in _solve() at line 180
   raise SolverProblemError(e)

lock

[dbarrosop]

I just hit this problem with an app that defined python = "^3.6" and a dependency that required python = ">=3.6,<3.8". How is it possible this fails to install under python 3.6 or 3.7?

This is the expected behavior, and to fix it you need to declare your project as compatible with Python ~2.7 || ^3.4.

I honestly don’t understand how is that the solution, what if your app depends on two libraries and one defines ~2.7 || ^3.4 and the other 3.4.*? Does that mean that’s not supported? Shouldn’t just be a matter of checking the current python version and making sure it’s compatible with the application and the dependencies?

[stale[bot]]

Closing this issue automatically because it has not had any activity since it has been marked as stale. If you think it is still relevant and should be addressed, feel free to open a new one.