No instance for ‘Data.Default.Class.Default Conn.TLSSettings’

Attempting to build smtp-mail 0.5.0.0 gives me:

Building library for smtp-mail-0.5.0.0...
[1 of 3] Compiling Network.Mail.SMTP.Auth ( Network/Mail/SMTP/Auth.hs, dist/build/Network/Mail/SMTP/Auth.o, dist/build/Network/Mail/SMTP/Auth.dyn_o )
[2 of 3] Compiling Network.Mail.SMTP.Types ( Network/Mail/SMTP/Types.hs, dist/build/Network/Mail/SMTP/Types.o, dist/build/Network/Mail/SMTP/Types.dyn_o )
[3 of 3] Compiling Network.Mail.SMTP ( Network/Mail/SMTP.hs, dist/build/Network/Mail/SMTP.o, dist/build/Network/Mail/SMTP.dyn_o )
Network/Mail/SMTP.hs:100:23: error: [GHC-39999]
    • No instance for ‘Data.Default.Class.Default Conn.TLSSettings’
        arising from a use of ‘def’
    • In the expression: def
      In an equation for ‘defaultTlsSettings’: defaultTlsSettings = def
    |
100 | defaultTlsSettings =  def
    |                       ^^^

Error: [Cabal-7125]

Perhaps it's the version of data-default or something?

Cheers

Reproduce the smtp-mail 0.5.0.0 build and inspect Network/Mail/SMTP.hs around line 100, where defaultTlsSettings is defined with def. Check the dependency versions and available Default instances for Conn.TLSSettings. Done means the package builds successfully with the intended TLS defaults.