JSON is needed as a dependency since it is used in build

[KristofferC]

Otherwise building the package errors:

Building Emoji_Entities ──→ `~/.julia/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/d45cd624dadedf039b74025d6ac4b200100a2e65/build.log`

PkgEval failed: Error building `Emoji_Entities`: 
ERROR: LoadError: ArgumentError: Package JSON not found in current path:
- Run `import Pkg; Pkg.add("JSON")` to install the JSON package.

(https://s3.amazonaws.com/julialang-reports/nanosoldier/pkgeval/by_hash/c3bb6df_vs_788b2c7/StrEntities.1.6.0-DEV-a896693d33.log)

[zsz00]

I had a same error

[George9000]

Same error which is causing issues with adding/building other packages. Details here.

[George9000]

More on the error. Julia 1.6 on macOS 10.15.7

julia> using JSON

julia> Pkg.build("Emoji_Entities")
    Building Emoji_Entities → `~/.julia/scratchspaces/44cfe95a-1eb2-52ea-b672-e2afdf69b78f/3cb6f96fb515feabc3f1348c3a504354a222a244/build.log`
ERROR: Error building `Emoji_Entities`:
ERROR: LoadError: ArgumentError: Package JSON not found in current path:
- Run `import Pkg; Pkg.add("JSON")` to install the JSON package.

Stacktrace:
 [1] require(into::Module, mod::Symbol)
   @ Base ./loading.jl:871
 [2] include(fname::String)
   @ Base.MainInclude ./client.jl:444
 [3] top-level scope
   @ none:5
in expression starting at /Users/foo/.julia/packages/Emoji_Entities/QJBuv/deps/build.jl:1
Stacktrace:
  [1] pkgerror(msg::String)
    @ Pkg.Types /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Types.jl:55
  [2] (::Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec})()
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1040
  [3] withenv(::Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec}, ::Pair{String, String}, ::Vararg{Pair{String, B} where B, N} where N)
    @ Base ./env.jl:161
  [4] (::Pkg.Operations.var"#108#112"{String, Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec}, Pkg.Types.PackageSpec})()
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1540
  [5] with_temp_env(fn::Pkg.Operations.var"#108#112"{String, Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec}, Pkg.Types.PackageSpec}, temp_env::String)
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1442
  [6] (::Pkg.Operations.var"#107#111"{Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec}, Pkg.Types.Context, Pkg.Types.PackageSpec, String, Pkg.Types.Project, String})(tmp::String)
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1515
  [7] mktempdir(fn::Pkg.Operations.var"#107#111"{Pkg.Operations.var"#81#86"{Bool, Pkg.Types.Context, String, Pkg.Types.PackageSpec}, Pkg.Types.Context, Pkg.Types.PackageSpec, String, Pkg.Types.Project, String}, parent::String; prefix::String)
    @ Base.Filesystem ./file.jl:729
  [8] mktempdir(fn::Function, parent::String) (repeats 2 times)
    @ Base.Filesystem ./file.jl:727
  [9] sandbox(fn::Function, ctx::Pkg.Types.Context, target::Pkg.Types.PackageSpec, target_path::String, sandbox_path::String, sandbox_project_override::Pkg.Types.Project)
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1481
 [10] build_versions(ctx::Pkg.Types.Context, uuids::Vector{Base.UUID}; verbose::Bool)
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:1021
 [11] build(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}, verbose::Bool)
    @ Pkg.Operations /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/Operations.jl:902
 [12] build(ctx::Pkg.Types.Context, pkgs::Vector{Pkg.Types.PackageSpec}; verbose::Bool, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:893
 [13] build
    @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:877 [inlined]
 [14] #build#70
    @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:73 [inlined]
 [15] build
    @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:72 [inlined]
 [16] #build#69
    @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:70 [inlined]
 [17] build
    @ /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:70 [inlined]
 [18] build(pkg::String; kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Pkg.API /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:69
 [19] build(pkg::String)
    @ Pkg.API /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/Pkg/src/API.jl:69
 [20] top-level scope
    @ REPL[13]:1

[ScottPJones]

Previously, on 1.5 and below the build worked (because the pre-built data is present), even with JSON missing.
What changed in 1.6 that causes this to break now?

Note: I checked in a change that avoids the problem, by putting a Project.toml in the deps directory that has the entry for JSON, since that's now supported.