```ruby
require File.expand_path('../../../spec_helper', __FILE__)

describe "Process.maxgroups" do
  it "returns the maximum number of gids allowed in the supplemental group access list" do
    Process.maxgroups.should be_kind_of(Fixnum)
  end

  it "sets the maximum number of gids allowed in the supplemental group access list" do
    n = Process.maxgroups
    Process.maxgroups = n + 1
    Process.maxgroups.should == n + 1
    Process.maxgroups = n
  end
end

describe "Process.maxgroups=" do
  it "needs to be reviewed for spec completeness"
end
```

Use -1 instead of Process.maxgroups + 1.
user
```ruby
require File.expand_path('../../../spec_helper', __FILE__)

describe "Process.maxgroups" do
  it "returns the maximum number of gids allowed in the supplemental group access list" do
    Process.maxgroups.should be_kind_of(Fixnum)
  end

  it "sets the maximum number of gids allowed in the supplemental group access list" do
    n = Process.maxgroups
    begin
      Process.maxgroups = n - 1
      Process.maxgroups.should == n - 1
    ensure
      Process.maxgroups = n
    end
  end
end

describe "Process.maxgroups=" do
  it "needs to be reviewed for spec completeness"
end
```
assistant