qmlformat: Unnecessary replacement of 'let' with 'var', leading to inline write errors

import QtQml

QtObject {
    function foo() {
        for (var i = 0; i < 5; ++i)
            console.log(i);
    }
}

qt.qmldom.writeOut: reparsed writeOut of /home/dev/main.qml has changes: - .components[""][0].objects[0].methods["foo"][0].body.astRelocatableDump value("<StatementList>\n <ForStatement forToken=\"for\" lparenToken=\"(\" rparenToken=\")\">\n <VariableDeclarationList commaToken=\"\">\n <PatternElement identifierToken=\"i\" bindingIdentifier=\"i\" type=\"5\" scope=\"2\" isForDeclaration=\"false\">\n <NumericLiteral value=\"0\" literalToken=\"0\">\n </NumericLiteral>\n </PatternElement>\n </VariableDeclarationList>\n <BinaryExpression op=\"15\" operatorToken=\"<\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n <NumericLiteral value=\"5\" literalToken=\"5\">\n </NumericLiteral>\n </BinaryExpression>\n <PreIncrementExpression incrementToken=\"++\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n </PreIncrementExpression>\n <ExpressionStatement>\n <CallExpression lparenToken=\"(\" rparenToken=\")\">\n <FieldMemberExpression name=\"log\" dotToken=\".\" identifierToken=\"log\">\n <IdentifierExpression name=\"console\" identiferToken=\"console\">\n </IdentifierExpression>\n </FieldMemberExpression>\n <ArgumentList commaToken=\"\" isSpreadElement=\"false\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n </ArgumentList>\n </CallExpression>\n </ExpressionStatement>\n </ForStatement>\n</StatementList>\n") + .components[""][0].objects[0].methods["foo"][0].body.astRelocatableDump value("<StatementList>\n <ForStatement forToken=\"for\" lparenToken=\"(\" rparenToken=\")\">\n <VariableDeclarationList commaToken=\"\">\n <PatternElement identifierToken=\"i\" bindingIdentifier=\"i\" type=\"5\" scope=\"1\" isForDeclaration=\"false\">\n <NumericLiteral value=\"0\" literalToken=\"0\">\n </NumericLiteral>\n </PatternElement>\n </VariableDeclarationList>\n <BinaryExpression op=\"15\" operatorToken=\"<\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n <NumericLiteral value=\"5\" literalToken=\"5\">\n </NumericLiteral>\n </BinaryExpression>\n <PreIncrementExpression incrementToken=\"++\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n </PreIncrementExpression>\n <ExpressionStatement>\n <CallExpression lparenToken=\"(\" rparenToken=\")\">\n <FieldMemberExpression name=\"log\" dotToken=\".\" identifierToken=\"log\">\n <IdentifierExpression name=\"console\" identiferToken=\"console\">\n </IdentifierExpression>\n </FieldMemberExpression>\n <ArgumentList commaToken=\"\" isSpreadElement=\"false\">\n <IdentifierExpression name=\"i\" identiferToken=\"i\">\n </IdentifierExpression>\n </ArgumentList>\n </CallExpression>\n </ExpressionStatement>\n </ForStatement>\n</StatementList>\n") 

qt.qmldom.writeOut: failure reformatting  "main.qml"
"Error while writing"