connection error about crystal-mysql HOT 13 CLOSED

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$ crystal deps update
Updating https://github.com/kemalcr/kemal.git
Updating https://github.com/luislavena/radix.git
Updating https://github.com/jeromegn/kilt.git
Updating https://github.com/RX14/multipart.cr.git
Updating https://github.com/jeromegn/slang.git
Updating https://github.com/crystal-lang/crystal-mysql.git
Updating https://github.com/crystal-lang/crystal-db.git
Updating https://github.com/kemalcr/kemal-session-file.git
Updating https://github.com/kemalcr/kemal-session.git
Installing kemal (0.17.4)
Installing radix (0.3.5)
Installing kilt (0.3.3)
Installing multipart (0.1.1)
Installing slang (1.4.1)
Installing mysql (0.3.1)
Installing db (0.3.3)
Installing kemal-session-file (0.3.0)
Installing kemal-session (master)
$ crystal spec -v
Error in spec/spec_helper.cr:10: instantiating 'DB:Module#open(String)'

    @@db : DB::Database = DB.open(DBURL)
                             ^~~~

in lib/db/src/db.cr:103: instantiating 'build_database(String)'

    build_database(uri)
    ^~~~~~~~~~~~~~

in lib/db/src/db.cr:117: instantiating 'build_database(URI)'

    build_database(URI.parse(connection_string))
    ^~~~~~~~~~~~~~

in lib/db/src/db.cr:121: instantiating 'DB::Database:Class#new(DB::Driver+, URI)'

    Database.new(driver_class(uri.scheme).new, uri)
             ^~~

in lib/db/src/db/database.cr:50: instantiating 'DB::Driver+#build_connection(DB::Database)'

        conn = @driver.build_connection(self).as(Connection)
                       ^~~~~~~~~~~~~~~~

in lib/mysql/src/mysql/driver.cr:3: instantiating 'MySql::Connection:Class#new(DB::Database)'

    MySql::Connection.new(db)
                      ^~~

in lib/mysql/src/mysql/connection.cr:22: instantiating 'read_packet(MySql::Protocol::HandshakeV10:Class)'

      handshake = read_packet(Protocol::HandshakeV10)
                  ^~~~~~~~~~~

in lib/mysql/src/mysql/connection.cr:57: instantiating 'read_packet()'

    read_packet do |packet|
    ^~~~~~~~~~~

in lib/mysql/src/mysql/connection.cr:47: instantiating 'build_read_packet()'

    packet = build_read_packet
             ^~~~~~~~~~~~~~~~~

in lib/mysql/src/mysql/connection.cr:65: instantiating 'MySql::ReadPacket:Class#new(TCPSocket+, MySql::Connection)'

    ReadPacket.new(@socket, self)
               ^~~

instance variable '@remaining' of MySql::ReadPacket must be Int32, not Nil

Error: instance variable '@remaining' is initialized inside a begin-rescue, so it can potentially be left uninitialized if an exception is raised and rescued

ERROR: Build failed: exit status 1

class MySql::ReadPacket
  include IO

  @length : Int32 = 0
  @remaining : Int32 = 0
  @seq : UInt8 = 0u8

  def initialize(@io : IO, @connection : Connection)
    begin
      ...
    rescue IO::EOFError
      raise DB::ConnectionLost.new(@connection)
    end
  end

require "mysql"

def go
  db = DB.open "something"
end

require "mysql"

class MyDb
  @@db = DB.open "anything"
end