HLedger supports aliases for accounts, including support for regex matching. There was incorrect parsing for these alias regexes, solved by adding the right 'between' and adding a line for allowing any character to be doubly escaped.
[
{
"endline": 1522,
"file": "hledger-lib/Hledger/Read/Common.hs",
"function": "regexaliasp",
"module": "Hledger.Read.Common",
"startline": 1518
}
][
{
"endline": 1523,
"file": "hledger-lib/Hledger/Read/Common.hs",
"function": "regexaliasp",
"module": "Hledger.Read.Common",
"startline": 1518
}
]