下のように何回やってもvagrant upでboxのダウンロードに失敗する状態になったときは、~/.vagrant.d/tmpの中身を全削除すると多分うまくいく。
$ vagrant up
Bringing machine 'vccw.dev' up with 'virtualbox' provider...
==> vccw.dev: Box 'miya0001/vccw' could not be found. Attempting to find and install...
vccw.dev: Box Provider: virtualbox
vccw.dev: Box Version: >= 0
==> vccw.dev: Loading metadata for box 'miya0001/vccw'
vccw.dev: URL: https://atlas.hashicorp.com/miya0001/vccw
==> vccw.dev: Adding box 'miya0001/vccw' (v2.14.0) for provider: virtualbox
vccw.dev: Downloading: https://atlas.hashicorp.com/miya0001/boxes/vccw/versions/2.14.0/providers/virtualbox.box
An error occurred while downloading the remote file. The error
message, if any, is reproduced below. Please fix this error and try
again.
SSL read: error:00000000:lib(0):func(0):reason(0), errno 60
$ vagrant up
Bringing machine 'vccw.dev' up with 'virtualbox' provider...
==> vccw.dev: Box 'miya0001/vccw' could not be found. Attempting to find and install...
vccw.dev: Box Provider: virtualbox
vccw.dev: Box Version: >= 0
==> vccw.dev: Loading metadata for box 'miya0001/vccw'
vccw.dev: URL: https://atlas.hashicorp.com/miya0001/vccw
==> vccw.dev: Adding box 'miya0001/vccw' (v2.14.0) for provider: virtualbox
vccw.dev: Downloading: https://atlas.hashicorp.com/miya0001/boxes/vccw/versions/2.14.0/providers/virtualbox.box
==> vccw.dev: Box download is resuming from prior download progress
An error occurred while downloading the remote file. The error
message, if any, is reproduced below. Please fix this error and try
again.
HTTP server doesn't seem to support byte ranges. Cannot resume.
$ vagrant up
# 以降、何度やっても同じ結果