swh-core Debian release 0.0.70-1~swh2

# gpg: Signature made Tue Oct  1 13:13:39 2019 UTC
# gpg:                using RSA key 3291900A8E20E2EF43F8F9D8DCAE90522E7122BF
# gpg: Can't check signature: No public key

# Conflicts:
#	debian/changelog

with Debian dir 4b6c4b644cf8f2445572eb33bceda83aaa2d333d

make mypy 0.730 pass cleanly again

with Debian dir cef1ea60375ca19de6caa651468b9fe207e06c6c

with Debian dir e0fe274d941fabbe254a413b5b0ea929ab08ea10

None is the default value, and sub-classes could possible not redefine it to be
an empty list. Hence, this change provides a sane default for downstream users.

to prevent erratic errors when using heavily multithreaded code.

`from aiohttp import Response` raises an `ImportError`.

swh-core Debian release 0.0.67-1~swh1

# Conflicts:
#	debian/changelog

with Debian dir bd1c7b7ef784564215cf3510754d42562c0bf4ff

Otherwise exceptions are silently ignored, until the transaction finishes.
And when the transaction fails, the returned error message is unhelpful.

This commit makes copy_to return the actual error message.

swh-core Debian release 0.0.66-1~swh1

# Conflicts:
#	debian/changelog

with Debian dir 020314726c2bb623dee09c1ff042bd16b4608576

debian/0.0.65-1_swh2

rebuild for missing dependencies.

# gpg: Signature made Tue Jul 16 12:50:14 2019 UTC
# gpg:                using RSA key 00E5837AF41B3A4FFD213305E8899295E3A59D47
# gpg:                issuer "david.douard@sdfa3.org"
# gpg: Can't check signature: No public key

# Conflicts:
#	debian/changelog