Previously, rockspec.lua checked if Lua 5.1 was installed to determine
if LuaRocks could build packages for Lua 5.1. This was not sufficient
since the Lua version does not matter as long as the development headers
for Lua 5.1 are available. So Lua 5.1 could be installed and the
LuaRocks packages could still fail to install.
Note: this also checks if a suitable version of Lua is installed since
the command will fail if Lua is not installed at all.
## Description
When passing the `--dev` flag to `luarocks`, it will prioritise `dev`
versions when resolving dependencies (treating `dev` or `scm` as greater
than a SemVer version) if the rockspec doesn't specify an upper version
constraint (which is often the case).
Dev packages are often unstable and may cause more problems, especially
for Windows users (an example I've seen is git for windows trying and
failing to checkout submodules).
For now , a good compromise between too many retries and not retrying at
all could be to try `luarocks install` from the root manifest first, but
to keep the `--dev` flag in `luarocks make`.
If that still causes problems, it might be better to fall back to
`luarocks make` without `--dev` first, and then to try `luarocks ---dev
make` as a last resort.
In rocks.nvim, we only fall back to adding the `--dev` flag if the
install error message contains the string `"No results matching query
were found"`; assuming that stable non-dev packages shouldn't depend on
dev packages.
