this derivation will be built:
  /nix/store/28dvln9knl911hy9l8mf59prfwysd62z-iets-nextest-0.1.0.drv
error: Cannot build '/nix/store/28dvln9knl911hy9l8mf59prfwysd62z-iets-nextest-0.1.0.drv'.
       Reason: builder failed with exit code 100.
       Output paths:
         /nix/store/9lil0p7izk8jjrj18akxd341ndmw4k3d-iets-nextest-0.1.0
       Last 25 log lines:
       >         PASS [  10.347s] (507/521) iets eval::tests::fetchurl_needs_a_sha256_in_every_mode
       >         PASS [   3.386s] (508/521) iets::fetchurl without_a_hash_no_evaluation_fetches_and_prefetch_gives_the_hash
       >         PASS [   4.809s] (509/521) iets::cache_hygiene concurrent_readers_and_writers_never_see_a_torn_entry
       >         PASS [  12.230s] (510/521) iets compile::cache::tests::a_changed_byte_never_makes_the_evaluator_read_past_its_env
       >         PASS [   3.601s] (511/521) iets::pure a_read_in_the_project_is_pure_and_one_above_it_is_not
       >         PASS [   5.779s] (512/521) iets::cli dash_f_names_the_file_in_the_native_namespace
       >         PASS [  12.191s] (513/521) iets eval::tests::fetchurl_checks_its_argument_like_nix
       >         PASS [   6.093s] (514/521) iets::fetchurl a_hashed_fetch_has_the_store_path_nix_gives
       >         PASS [   8.612s] (515/521) iets::profile a_builtin_names_itself_in_a_frame
       >         PASS [  28.910s] (516/521) iets::profile a_folded_line_is_a_stack_and_a_count
       >         PASS [  42.456s] (517/521) iets eval::tests::pure_eval_answers_like_nix
       >         SLOW [> 60.000s] (-------) iets api::run::tests::helper_fibers_read_the_ir_cache
       >         PASS [  50.213s] (518/521) iets::profile an_allocation_profile_accounts_for_the_arena
       >         PASS [  61.264s] (519/521) iets api::run::tests::helper_fibers_read_the_ir_cache
       >         SLOW [> 60.000s] (-------) iets runtime::value::tests::union_iteration_merges_like_a_fold
       >         SLOW [> 60.000s] (-------) iets syntax::tests::deep_nesting_ends_with_an_error
       >         PASS [  89.156s] (520/521) iets syntax::tests::deep_nesting_ends_with_an_error
       >         SLOW [>120.000s] (-------) iets runtime::value::tests::union_iteration_merges_like_a_fold
       >         SLOW [>180.000s] (-------) iets runtime::value::tests::union_iteration_merges_like_a_fold
       >         SLOW [>240.000s] (-------) iets runtime::value::tests::union_iteration_merges_like_a_fold
       >         PASS [ 241.726s] (521/521) iets runtime::value::tests::union_iteration_merges_like_a_fold
       > ------------
       >      Summary [ 248.464s] 521 tests run: 520 passed (3 slow), 1 failed, 5 skipped
       >         FAIL [   3.123s] (482/521) iets trace::tests::dedupe_of_many_repeats_is_linear
       > error: test run failed
       For full logs, run:
         nix log /nix/store/28dvln9knl911hy9l8mf59prfwysd62z-iets-nextest-0.1.0.drv