No canonical conversion from ℚ to ‾𝔽ₚ?

[user202729]

Steps To Reproduce

p = 2**127 - 1
F = GF(p)

F.algebraic_closure()(F(5/2))  # okay
F.algebraic_closure()(5/2)  # error?

Expected Behavior

The last line also works.

Actual Behavior

The last line errors out.

Side note, the motivation is the following.

p = 2**5-1
F = GF(p)
E = EllipticCurve(F, [0, 6, 0, 1, 0])
E.change_ring(F.algebraic_closure()).isogenies_prime_degree(5)  # errors?

Checklist

• I have searched the existing issues for a bug report that matches the one I want to file, without success.
• I have read the documentation and troubleshoot guide

[JohnCremona]

I agree that there should be a conversion from QQ to any field of characteristic p which works for rationals with non-negative valuation, i.e. with denominator prime to p.