I just left a comment on that issue, but also leaving here so I can find this thread again later.
I’m getting this same error in my production app, and it’s showing up a lot. After upgrading to crystal 0.34, I noticed I get it in development a lot too.
web | ▸ Exception Error writing to socket: Broken pipe (IO::Error)
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/socket.cr:82:13 in 'unbuffered_write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:152:14 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/http/server/response.cr:219:11 in 'unbuffered_write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:218:5 in 'flush'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:156:7 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/http/server/response.cr:86:7 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io.cr:1121:7 in 'copy'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/http/server/handlers/static_file_handler.cr:81:9 in 'call'
web | from lib/lucky/src/charms/static_file_handler.cr:5:5 in 'call'
web | ▸ Unhandled exception Error writing to socket: Broken pipe (IO::Error)
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/socket.cr:82:13 in 'unbuffered_write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:152:14 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/http/server/response.cr:219:11 in 'unbuffered_write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:218:5 in 'flush'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io/buffered.cr:151:7 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/http/server/response.cr:86:7 in 'write'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io.cr:472:7 in 'write_utf8'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/string.cr:4413:5 in 'to_s'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io.cr:175:5 in '<<'
web | from /Users/jeremywoertink/.asdf/installs/crystal/0.34.0/src/io.cr:189:5 in 'print'
web | from lib/lucky/src/lucky/text_response.cr:26:5 in 'print'