regression in backtrace printing during precompile

[vtjnash]

I introduced a random error into a package (ignore the error itself). Observe that the 'Some type information was truncated' line is printing, which should not be present here and the {...} which is irrecoverably discarding information. Caused by #49795.

(@v1.8) pkg> precompile OrdinaryDiffEq
Precompiling OrdinaryDiffEq
  ✗ OrdinaryDiffEq
  0 dependencies successfully precompiled in 21 seconds. 124 already precompiled.

ERROR: The following 1 direct dependency failed to precompile:

OrdinaryDiffEq [1dea7af3-3e70-54e6-95c3-0bf5283fa5ed]

Failed to precompile OrdinaryDiffEq [1dea7af3-3e70-54e6-95c3-0bf5283fa5ed] to "/home/vtjnash/.julia/compiled/v1.10/OrdinaryDiffEq/jl_5X8d7m".
ERROR: LoadError: syntax: invalid let syntax around /home/vtjnash/.julia/packages/FastClosures/3LNoZ/src/FastClosures.jl:51
Stacktrace:
 [1] top-level scope
   @ ~/.julia/packages/OrdinaryDiffEq/EQy59/src/initialize_dae.jl:356
 [2] include(mod::Module, _path::String)
   @ Base ./Base.jl:488
 [3] include(x::String)
   @ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/EQy59/src/OrdinaryDiffEq.jl:4
 [4] top-level scope
   @ ~/.julia/packages/OrdinaryDiffEq/EQy59/src/OrdinaryDiffEq.jl:164
 [5] include(mod::Module, _path::String)
   @ Base ./Base.jl:488 [inlined]
 [6] include_package_for_output(pkg::Base.PkgId, input::String, depot_path::Vector{…}, dl_load_path::Vector{…}, load_path::Vector{…}, concrete_deps::Vector{…}, source::Nothing)
   @ Base ./loading.jl:2126
 [7] top-level scope
   @ stdin:3
Some type information was truncated. Use `show(err)` to see complete types.
in expression starting at /home/vtjnash/.julia/packages/OrdinaryDiffEq/EQy59/src/initialize_dae.jl:356
in expression starting at /home/vtjnash/.julia/packages/OrdinaryDiffEq/EQy59/src/OrdinaryDiffEq.jl:1
in expression starting at stdin:3

[vtjnash]

Fixed by #50598