Pkg gc throws unknown string escape error

Can someone give me a hint on how to fix this.
Which file contains the wrong string escape?

Julia Version 1.3.1
Commit 2d5741174c (2019-12-30 21:36 UTC)
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: Intel(R) Core(TM) i5-8365U CPU @ 1.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-6.0.1 (ORCJIT, skylake)


(v1.3) pkg> gc
ERROR: Pkg.TOML.ParserError(1478, 1479, "unknown string escape: `\\x24`")

...and 26 more exception(s).

Stacktrace:
 [1] parse(::Base.GenericIOBuffer{Array{UInt8,1}}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\ext\TOML\src\TOML.jl:37
 [2] parse at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\ext\TOML\src\TOML.jl:44 [inlined]
 [3] (::Pkg.API.var"#collect_usage!#78")(::Dict{String,Dates.DateTime}, ::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:302
 [4] #gc#63(::Dates.Day, ::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Pkg.API.gc), ::Pkg.Types.Context) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:321
 [5] gc at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\API.jl:278 [inlined]
 [6] do_gc!(::Dict{Symbol,Any}, ::Array{String,1}, ::Dict{Symbol,Any}) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\REPLMode.jl:474
 [7] #invokelatest#1(::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}, ::typeof(Base.invokelatest), ::Any, ::Any, ::Vararg{Any,N} where N) at .\essentials.jl:709
 [8] invokelatest(::Any, ::Any, ::Vararg{Any,N} where N) at .\essentials.jl:708
 [9] do_cmd!(::Pkg.REPLMode.Command, ::REPL.LineEditREPL) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\REPLMode.jl:412
 [10] #do_cmd#23(::Bool, ::typeof(Pkg.REPLMode.do_cmd), ::REPL.LineEditREPL, ::String) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\REPLMode.jl:391
 [11] do_cmd at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\REPLMode.jl:387 [inlined]
 [12] (::Pkg.REPLMode.var"#28#31"{REPL.LineEditREPL,REPL.LineEdit.Prompt})(::REPL.LineEdit.MIState, ::Base.GenericIOBuffer{Array{UInt8,1}}, ::Bool) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\Pkg\src\REPLMode.jl:619
 [13] #invokelatest#1 at .\essentials.jl:709 [inlined]
 [14] invokelatest at .\essentials.jl:708 [inlined]
 [15] run_interface(::REPL.Terminals.TextTerminal, ::REPL.LineEdit.ModalInterface, ::REPL.LineEdit.MIState) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\REPL\src\LineEdit.jl:2306
 [16] run_frontend(::REPL.LineEditREPL, ::REPL.REPLBackendRef) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\REPL\src\REPL.jl:1045
 [17] run_repl(::REPL.AbstractREPL, ::Any) at D:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.3\REPL\src\REPL.jl:201
 [18] (::Base.var"#770#772"{Bool,Bool,Bool,Bool})(::Module) at .\client.jl:382
 [19] #invokelatest#1 at .\essentials.jl:709 [inlined]
 [20] invokelatest at .\essentials.jl:708 [inlined]
 [21] run_main_repl(::Bool, ::Bool, ::Bool, ::Bool, ::Bool) at .\client.jl:366
 [22] exec_options(::Base.JLOptions) at .\client.jl:304
 [23] _start() at .\client.jl:460

I could narrow it down a bit by using Debugger.jl

https://github.com/JuliaLang/julia/issues/34781