Granite ORM + fiber + mysql = Unexpected EOF (Exception)? - crystal-lang

Question

Is working with Fibers in Granite possible? I didn't have a reason to believe otherwise, until I attempted to write some code for it. I am attempting to learn to work with Fibers, so perhaps incorrect fiber implementation could also be a cause. The following code results in an exception. Any hints to resolve this?
lines = File.read_lines INVENTORY_FILE
channel = Channel(Int32).new(199)
lines[0..200].each do |line|
row_number += 1
proc = ->(line : NamedTuple(item_number: String) do
spawn do
sku = Sku.find_by :item_number, item_number
channel.send(1)
end
end
proc.call({ line: line })
end
199.times do |i|
channel.receive
end
The above results in the following repeated exception starting from the very first fiber's attempt to access the DB. I've ensured that MySQL is in a working state and that the code works when fibers are not in use:
Unexpected EOF (Exception)
from lib/mysql/src/mysql/read_packet.cr:38:18 in 'read_byte!'
from lib/mysql/src/mysql/read_packet.cr:63:5 in 'read_int'
from lib/mysql/src/mysql/packets.cr:13:7 in 'read'
from lib/mysql/src/mysql/connection.cr:63:14 in 'read_packet'
from lib/mysql/src/mysql/connection.cr:22:19 in 'initialize'
from lib/mysql/src/mysql/connection.cr:4:3 in 'new'
from lib/mysql/src/mysql/driver.cr:3:5 in 'build_connection'
from lib/db/src/db/pool.cr:255:3 in 'build_resource'
from lib/db/src/db/pool.cr:34:22 in 'checkout'
from lib/db/src/db/pool.cr:65:7 in 'checkout_some'
from lib/db/src/db/database.cr:99:7 in 'checkout_some'
from lib/db/src/db/pool_prepared_statement.cr:35:24 in 'build_statement'
from lib/db/src/db/pool_prepared_statement.cr:53:22 in 'initialize'
from lib/db/src/db/pool_prepared_statement.cr:11:5 in 'new'
from lib/db/src/db/database.cr:89:7 in 'build_prepared_statement'
from lib/db/src/db/database.cr:7:15 in 'fetch_or_build_prepared_statement'
from lib/db/src/db/session_methods.cr:23:9 in 'build'
from lib/db/src/db/query_methods.cr:38:7 in 'query'
from lib/granite/src/granite/querying.cr:53:12 in 'find_by'
from /usr/share/crystal/src/kernel.cr:0:3 in '~procProc(Nil)'
from /usr/share/crystal/src/fiber.cr:255:3 in 'run'
from /usr/share/crystal/src/concurrent.cr:0:3 in '~proc2Proc(Fiber, (IO::FileDescriptor | Nil))'
from ???