Pkg's gc failing due to stray characters in manifest_usage.toml

[BeastyBlacksmith]

The error message is

[ Info: We haven't cleaned this depot up for a bit, running Pkg.gc()...
┌ Error: GC failed
│   exception =
│    TOML Parser error:
│    ~/.julia/logs/manifest_usage.toml:1103:0 error: invalid bare key character: '\n'
│      3Z
│        ^
└ @ Pkg /buildworker/worker/package_linux64/build/usr/share/julia/stdlib/v1.7/Pkg/src/Pkg.jl:644

[BeastyBlacksmith]

There is a suspiciously looking 3Z on this line in the file

[["~/.julia/dev/OCTOPOS/web/Manifest.toml"]]
time = 2021-11-10T11:07:35.083Z
3Z

But there are also more lines like this in the file.
Failing on 1.7.0 and 1.6.2

[Seelengrab]

The line with time = is a valid ISO-8601 datetime string with timezone information (that's the Z, here for Zulu or UTC time) - what shouldn't be there is imo the lonely 3Z. Does this occur at the end somewhere? It looks like a reused buffer with different lengths didn't get properly truncated when writing to it again 🤔

[giordano]

Yeah, in the Yggdrasil buildmachine we have plenty of those lines. I suspect that may be due to parallel access to the file.

[jonniedie]

Whats the best way to handle this if it happens to me? Just delete that file and let it rebuild?

[giordano]

In Yggdrasil that file is close to 1 million lines, so for me it's easier to delete it than trying to fix it (something which I actually tried once, but gave up after half an hour when I realised I was at 10% of the file)

[ericphanson]

Xref #1664

[Eben60]

Apparently the same error.
macOS ARM , Julia 1.8.3 & 1.8.4
Rebuilding Manifest doesn't help.

(MSCal) pkg> gc
ERROR: TOML Parser error:
/Users/elk/.julia/logs/manifest_usage.toml:94:0 error: invalid bare key character: '\n'
  747Z
      ^
Stacktrace:
  [1] parse
    @ ./toml_parser.jl:441 [inlined]
  [2] Base.CachedTOMLDict(p::Base.TOML.Parser, path::String)
    @ Base ./loading.jl:222
  [3] (::Base.var"#894#895"{String, Base.TOMLCache})()
    @ Base ./loading.jl:277
  [4] lock(f::Base.var"#894#895"{String, Base.TOMLCache}, l::ReentrantLock)
    @ Base ./lock.jl:185
  [5] parsed_toml
    @ ./loading.jl:274 [inlined]
  [6] parse_toml
    @ /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/Types.jl:58 [inlined]
  [7] (::Pkg.API.var"#reduce_usage!#175")(f::Function, usage_filepath::String)
    @ Pkg.API /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/API.jl:500
  [8] gc(ctx::Pkg.Types.Context; collect_delay::Dates.Day, verbose::Bool, force::Bool, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/API.jl:511
  [9] gc (repeats 2 times)
    @ /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/API.jl:469 [inlined]
 [10] do_cmd!(command::Pkg.REPLMode.Command, repl::REPL.LineEditREPL)
    @ Pkg.REPLMode /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/REPLMode/REPLMode.jl:406
 [11] do_cmd(repl::REPL.LineEditREPL, input::String; do_rethrow::Bool)
    @ Pkg.REPLMode /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/REPLMode/REPLMode.jl:387
 [12] do_cmd
    @ /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/REPLMode/REPLMode.jl:377 [inlined]
 [13] (::Pkg.REPLMode.var"#24#27"{REPL.LineEditREPL, REPL.LineEdit.Prompt})(s::REPL.LineEdit.MIState, buf::IOBuffer, ok::Bool)
    @ Pkg.REPLMode /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/Pkg/src/REPLMode/REPLMode.jl:551
 [14] #invokelatest#2
    @ ./essentials.jl:729 [inlined]
 [15] invokelatest
    @ ./essentials.jl:726 [inlined]
 [16] run_interface(terminal::REPL.Terminals.TextTerminal, m::REPL.LineEdit.ModalInterface, s::REPL.LineEdit.MIState)
    @ REPL.LineEdit /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/LineEdit.jl:2510
 [17] run_frontend(repl::REPL.LineEditREPL, backend::REPL.REPLBackendRef)
    @ REPL /Applications/Julia-1.8.app/Contents/Resources/julia/share/julia/stdlib/v1.8/REPL/src/REPL.jl:1248
 [18] (::REPL.var"#49#54"{REPL.LineEditREPL, REPL.REPLBackendRef})()
    @ REPL ./task.jl:484