doctest() fails when git is not installed

[glennmoy]

We are running CI jobs using a docker image that doesn't have git installed (stacktrace below) and the jobs have been failing since 0.27.20.

Looking at the changes in https://gitlab.invenia.ca/invenia/Metrics.jl/-/pipelines/202985, we can see there is an extra call to git that happens outside of a try catch block a few lines below, and this is where we fail in the stacktrace (see below).

Is this expected behaviour? Should Documenter work without needing git?
Would setting disable_git avoid this error?

Thanks in advance!

Error: Doctesting failed
│   exception =
│    Unable to find `git`
│    Stacktrace:
│      [1] error(s::String)
│        @ Base ./error.jl:33
│      [2] git(; kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
│        @ Documenter.Utilities ~/.julia/packages/Documenter/lG4NP/src/Utilities/Utilities.jl:848
│      [3] git
│        @ ~/.julia/packages/Documenter/lG4NP/src/Utilities/Utilities.jl:847 [inlined]
│      [4] git_remote_head_branch(varname::String, root::String; remotename::String, fallback::String)
│        @ Documenter.Utilities ~/.julia/packages/Documenter/lG4NP/src/Utilities/Utilities.jl:797
│      [5] git_remote_head_branch
│        @ ~/.julia/packages/Documenter/lG4NP/src/Utilities/Utilities.jl:797 [inlined]
│      [6] Documenter.Writers.HTMLWriter.HTML()
│        @ Documenter.Writers.HTMLWriter ~/.julia/packages/Documenter/lG4NP/src/Writers/HTMLWriter.jl:443
│      [7] (::Documenter.var"#all_doctests#32"{Bool, Vector{Regex}, Vector{Module}})()
│        @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:941
│      [8] macro expansion
│        @ ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:962 [inlined]
│      [9] macro expansion
│        @ /buildworker/worker/package_linuxaarch64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
│     [10] doctest(source::String, modules::Vector{Module}; fix::Bool, testset::String, doctestfilters::Vector{Regex})
│        @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:962
│     [11] doctest(package::Module; manual::Bool, testset::Nothing, kwargs::Base.Iterators.Pairs{Union{}, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
│        @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:897
│     [12] doctest(package::Module)
│        @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:884
│     [13] macro expansion
│        @ /builds/invenia/Metrics.jl/test/runtests.jl:29 [inlined]
│     [14] macro expansion
│        @ /buildworker/worker/package_linuxaarch64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
│     [15] top-level scope
│        @ /builds/invenia/Metrics.jl/test/runtests.jl:29
│     [16] include(fname::String)
│        @ Base.MainInclude ./client.jl:444
│     [17] top-level scope
│        @ none:6
│     [18] eval
│        @ ./boot.jl:360 [inlined]
│     [19] exec_options(opts::Base.JLOptions)
│        @ Base ./client.jl:261
│     [20] _start()
│        @ Base ./client.jl:[485](https://gitlab.invenia.ca/invenia/Metrics.jl/-/jobs/1725827#L485)
└ @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:951
Doctests: Metrics: Test Failed at /root/.julia/packages/Documenter/lG4NP/src/Documenter.jl:962
  Expression: all_doctests()
Stacktrace:
 [1] macro expansion
   @ ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:962 [inlined]
 [2] macro expansion
   @ /buildworker/worker/package_linuxaarch64/build/usr/share/julia/stdlib/v1.6/Test/src/Test.jl:1151 [inlined]
 [3] doctest(source::String, modules::Vector{Module}; fix::Bool, testset::String, doctestfilters::Vector{Regex})
   @ Documenter ~/.julia/packages/Documenter/lG4NP/src/Documenter.jl:962

[mortenpi]

This is an oversight from #1862 --- it should print a warning and return the fallback when we can't find git. I presume you were getting warnings before?

[glennmoy]

Handle missing Git in git_remote_head_branch #1871

yes, that's correct. Thanks for taking a look!