The documentation for the print function specifies that the input
argument is coerced to string.  However, if bytes are passed and the
file= parameter points to a file open for binary write, the error
message produced is:

>>> out = open('temp', 'wb')
>>> print(b'abc', file=out)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: write() argument 1 must be bytes or buffer, not str

which is, to say the least, confusing, since I clearly passed print a
bytes object as argument 1.

How would you propose to fix this?  print() should certainly not catch
all TypeErrors and raise a new one...

Maybe exception chaining could be used, so that print raises a TypeError
of its own with the cause being the original message?

The problem here is not the bytes object: it is correctly coerced to a
string. 

The problem is the binary stream, which cannot accept strings.
We could maybe detect common errors and add a check at the beginning of
the print() function? something like
    if isinstance(file, (BufferedWriter, RawIOBase)):
        raise ValueError("file should be a text stream")