solana: Stake accounts stuck deactivating

Problem

A collection of stake accounts on mainnet-beta are “stuck” in the deactivating state. All 14 of them happen to have been delegated and deactivated in epoch 16. The immediate cause of this issue is that the StakeHistory sysvar reports 0 lamports as deactivating for epoch 16, so that the share of deactivating stake allotted to each of these accounts is also 0.

Here is the output of solana stake-history for nearby epochs:

    19      5071038.34127776          400.39543424           15.31303968 SOL
     18      5020338.33040928        50700.01086848           15.31303968 SOL
     17       5020338.3381264            0.09771712           15.41847392 SOL
     16      4970322.82421824        50000.20086848                     0 SOL
     15        5020319.828784            2.99315136        49999.99771712 SOL

15.31303968 SOL corresponds to the amount of stake “stuck” in these 14 accounts.

Addresses:

[
    ZKbZsMhUJMp7MfcFmkYqtipcgcJxi33GiCyNMTQKUV9,
    2371aoQkSwkqoceYzA7ycSaLaW2takvLv52u8FDYmFJU,
    3Sxhqd87eGHzRCHW1wK8EbkVVpAqLeEoYSYQHpuKh9EZ,
    3fu3BEhLWP1Zm6PyjrSQWDkwMEmiUgnQy6xXDrRxeQg9,
    6uMvSMbEux6VLE2D4JY471hmG74PUDTvAqc2ggTi6Zg3,
    7SGCyBSwNCbhC1FxPW5FFTuyyoNqo1kWBN3P2ua881zJ,
    7cg9whPgWFZbCTn52AEjUaUAJk44n2jgpZWjzYPPtSVR,
    9S1gnNB1yQy3j1uTqrLVX6UqzQYKpHbdBtwHb4vjUfYd,
    9dUAdJcdKQ5ZDsJg4sWYTtCuYgtQbQwnXKFqJQGjTnEH,
    Bo1PzDvwSMorNW7dMsbT69aRuJox6aXKWeGLyu6FYikU,
    CVUysRJyjdRey56q92bTuzgNVot99uhdo5aSRH6qMBav,
    D59zLU646AvzXyhxMSZvFT67JiggCMYzUzWKB47qNhcn,
    DzHX8tfrE7uhSDpo9m1pcGHbH2sStmDuipRbdQYBRsKw,
    F6Ni2rYtY74h8ju7neMbUMC1afccDoELFEHhHiwY38ui,
]

@t-nelson reported seeing this issue locally when delegating and deactivating stake in the same epoch, but it does not always reproduce.

Proposed Solution

???

CC: @garious