I repeated this issue many times and still do not have 100% reproducible steps. Incredible hard to repeat.

$ pijul id li
No identities found. Use `pijul identity new` to create one.
If you have created a key in the past, you may need to migrate via `pijul identity repair`
$ pi id new
✔ Unique identity name · default
✔ Display name · Mike
✔ Email (leave blank for none) · mpech@tuta.io
✔ Do you want to change the encryption? (Current status: not encrypted) · no
✔ Do you want this key to expire? (Current expiry: never) · no
✔ Do you want to link this identity to a remote? · no
$ pijul id new
✔ Unique identity name · dd
✔ Display name · Mike
✔ Email (leave blank for none) · mpech@tuta.io
✔ Do you want to change the encryption? (Current status: not encrypted) · no
✔ Do you want this key to expire? (Current expiry: never) · no
✔ Do you want to link this identity to a remote? · no
$ pijul id li
Identities
├─ default
│  ├─ Display name: Mike
│  ├─ Email: mpech@tuta.io
│  ├─ Login: <NO USERNAME>@<NO ORIGIN>
│  ├─ Public key
│  │  ├─ Key: AGB33NJ2W3m9ZnGsE9AkFSHwKf9aSEUwd5qLVERq8hdS
│  │  ├─ Version: 0
│  │  ├─ Algorithm: Ed25519
│  │  └─ Expiry: Never
│  ├─ Secret key
│  │  ├─ Version: 0
│  │  ├─ Algorithm: Ed25519
│  │  └─ Encryption: None
│  └─ Last updated: 2022-11-26 07:15:51 (UTC)
└─ dd
   ├─ Display name: Mike
   ├─ Email: mpech@tuta.io
   ├─ Login: <NO USERNAME>@<NO ORIGIN>
   ├─ Public key
   │  ├─ Key: Gy76LzhsbQCRQkBTX7Cnpsb13KwD65smz4JtPp8JHpYv
   │  ├─ Version: 0
   │  ├─ Algorithm: Ed25519
   │  └─ Expiry: Never
   ├─ Secret key
   │  ├─ Version: 0
   │  ├─ Algorithm: Ed25519
   │  └─ Encryption: None
   └─ Last updated: 2022-11-26 07:15:51 (UTC)
$

Choose dd replace by default.

$ pijul id ed
✔ Select identity · dd
Editing identity: dd
✔ Unique identity name · default
✔ Display name · Mike
✔ Email (leave blank for none) · mpech@tuta.io
✔ Do you want to change the encryption? (Current status: not encrypted) · no
✔ Do you want this key to expire? (Current expiry: never) · no
✔ Do you want to link this identity to a remote? · no
$

Corruption, double }} in json file.

$ pijul id li
No identities found. Use `pijul identity new` to create one.
If you have created a key in the past, you may need to migrate via `pijul identity repair`
$ cat default/secret_key.json 
{
  "version": 0,
  "algorithm": "Ed25519",
  "key": "EJKxBfRBZjK4mTsD8YJ3fqfQKhgraKL8AXB4eXuCHSPTBNgaDrjGQsXgHXLCB8JaSeko5pGQe7Xm723RnB5Wthn"
}}
$