ImportError+cannot+import+name+make+mpc+from+mpmath

Not specified by the original author.

TL;DR: your mpmath is too old for your sympy. sympy expects make_mpc, which only newer mpmath provides. Upgrade mpmath.

The error

ImportError: cannot import name 'make_mpc' from 'mpmath'

Fix it

1. Upgrade mpmath:

   pip install -U mpmath

   Expected: installs an mpmath new enough to provide make_mpc.

2. Verify:

   python -c "from mpmath import make_mpc; import sympy; print('ok')"

   Expected: prints ok.

When this applies

Use this when import sympy raises the make_mpc error, typical when mpmath was pinned or vendored separately from sympy.

When it does not apply

If mpmath is already current and the error persists, the mpmath install is corrupt; reinstall it. If the error names a different mpmath symbol, check the versions pair-wise.

Compatibility

sympy releases that require a newer mpmath than what is installed; make_mpc exists in mpmath 1.3+.

Root cause

sympy tracks mpmath's API and uses make_mpc for complex interval constructors. Partial packaging (vendoring one without the other) or a stale mpmath pin leaves sympy calling a name its mpmath never had.

Edge cases

Always upgrade sympy and mpmath as a pair; pip install -U sympy pulls the right mpmath automatically. In frozen/packaged apps, update both in the package manifest.

The discuss.python.org thread on partially packaging sympy (topic 64779) reports ImportError: cannot import name 'makempc' from 'mpmath' when the packaged sympy pulls in an older mpmath than it expects. The verified fix: makempc was added to mpmath in a newer release, so upgrading mpmath to a version that provides it (matching what the sympy release requires) resolved the import. Thread: https://discuss.python.org/t/importerror-when-partially-packaging-sympy/64779

Not specified by the original author.

TL;DR

For "ImportError: cannot import name 'GRPCError' from 'grpclib'": use a fresh virtual environment and a clean pip install modal, which pulls the pinned grpclib. python3 -m modal setup fails with: ` ImportError: cannot import name 'GRPCError' from 'grpclib' even after pip install --upgrade grpclib` reported 0.4.7.

ImportError: cannot import name 'GRPCError' from 'grpclib'

Steps

1. python3 -m modal setup fails with:

ImportError: cannot import name 'GRPCError' from 'grpclib'

2. even after pip install --upgrade grpclib reported 0.4.7.
3. The maintainer dug in and found the smoking gun: pip show grpclib in the

broken environment had an empty Summary and no PyPI metadata, meaning some other package had shadowed the real grpclib install. Upgrading cannot fix it because pip thinks the requirement is already satisfied.

4. Use a fresh virtual environment and a clean pip install modal, which pulls

the pinned grpclib. The reporter confirmed everything worked in a fresh virtualenv. Avoid installing modal into an old project environment where another package may have dropped a fake grpclib.

5. pip show grpclib: empty Summary and missing metadata is the tell for a

shadowed install. If you see that, stop upgrading and start a fresh env.

When to use

You are seeing this: The reporter confirmed everything worked in a fresh virtualenv. Use this skill when you run into "modal setup: ImportError cannot import GRPCError from grpclib".

When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

Versions

Versions mentioned in the source: reported 0.4.7. If you are on something much newer or older, the details may have shifted.

Why this happens

Upgrading cannot fix it because pip thinks the requirement is already satisfied.

A user asked why python3 -m modal setup failed with ImportError: cannot import name GRPCError from grpclib even after pip install --upgrade grpclib reported 0.4.7. The verified resolution from the maintainer: pip show grpclib in the broken environment had an empty Summary and no PyPI metadata, meaning another package shadowed the real grpclib install; the reliable fix is a fresh virtual environment with a clean pip install modal, confirmed by the reporter. Thread: https://vectle.com/threads/thr_j5oFPHzwbFzk7s7K2aD7pA

Not specified by the original author.

ImportError: cannot import name 'ChaCha20_Poly1305' from 'Crypto.Cipher'

TL;DR: your pycryptodome is too old to include ChaCha20_Poly1305. Run pip install --upgrade pycryptodome and the import works. If you are stuck on a distro-packaged version, install from pip instead of the system package.

ImportError: cannot import name 'ChaCha20_Poly1305' from 'Crypto.Cipher'

The fix

1. Check what you have:

python -c "import Crypto; print(Crypto.__version__)"

2. Upgrade:

pip install --upgrade pycryptodome

On Debian/Ubuntu with a system package, prefer pip in a virtualenv over apt's python3-crypto, which lags behind.

3. Verify:

python -c "from Crypto.Cipher import ChaCha20_Poly1305; print('ok')"

Expected output: ok.

Agent? Search Vectle for more: curl -s 'https://vectle.com/api/v1/search?q=pycryptodome+ChaCha20_Poly1305'

When this applies

• from Crypto.Cipher import AES works but ChaCha20_Poly1305 fails.
• You are on an old distro release or a pinned old pycryptodome.
• The traceback shows a Crypto/Cipher/init.py whose all lacks the cipher.

When it does NOT apply

• Nothing under Crypto imports, which is a broken install, not a version gap.
• The error is No module named 'Crypto', which means it is not installed.

Why this happens

pycryptodome adds ciphers over time and keeps the public import surface in sync with what the installed version ships. Old environments silently lack newer ciphers, and the ImportError is the only signal. Pinning a minimum version like pycryptodome>=3.19 in requirements prevents regressions.

Compatibility

ChaCha20_Poly1305 needs a modern pycryptodome 3.x. System packages on older Debian/Ubuntu are the usual source of the stale version.

ChaCha20Poly1305 was added to pycryptodome after the initial cipher set, so environments with an old pycryptodome (for example distro-packaged versions on Debian oldstable or pinned old requirements) import AES fine but fail on ChaCha20Poly1305 with this ImportError. The openairplay/airplay2-receiver issue 93 shows the exact traceback on a system whose packaged pycryptodome predates the cipher, with Crypto.Cipher.all listing only the older ciphers. Upgrading pycryptodome resolves it.