(FunctionClauseError) no function clause matching in Keyword.delete_key/3

[michaelstalker]

We encountered an error in one of our apps that uses Timex, which uses Tzdata. Here's the stacktrace:

Elixir.FunctionClauseError: no function clause matching in Keyword.delete_key/3
  File "lib/tzdata/util.ex", line 73, in Tzdata.Util.first_matching_weekday_in_month/4
  File "lib/tzdata/util.ex", line 329, in Tzdata.Util.time_for_rule/2
  File "lib/tzdata/period_builder.ex", line 161, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  File "lib/tzdata/period_builder.ex", line 180, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  File "lib/tzdata/period_builder.ex", line 185, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  File "lib/tzdata/period_builder.ex", line 180, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  File "lib/tzdata/period_builder.ex", line 185, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  File "lib/tzdata/period_builder.ex", line 180, in Tzdata.PeriodBuilder.calc_periods_for_year/9
  Module "Elixir.Tzdata.ReleaseUpdater", in Tzdata.ReleaseUpdater.init/1

The four arguments to Tzdata.Util.first_matching_weekday_in_month/4 are 1932, 4, 7, and [], respectively.

We're using Timex 3.6.1 and Tzdata 1.0.1.

[lau]

That error with those line numbers look suspiciously like Tzdata 1.0.0 (as opposed to 1.0.1). Would you mind double checking that you are indeed running 1.0.1 and not 1.0.0 (or earlier)?

[michaelstalker]

It turns out that we were running an older version of the app 🤦‍♂ I'll close this ticket. Thanks for replying so quickly!

[lau]

No worries :)