Hidden Modules

To see hidden modules a user can do:

$ module --show_hidden avail
$ module --show_hidden spider

or:

$ module --all avail
$ module --all spider

or:

$ module -A avail
$ module -A spider

To hide modules, a site can name a module with a leading “.” for the version or the name:

The following tree contains 3 modules, 2 hidden and one not:

$ tree -a modulefiles

modulefiles
├── .B
│   └── 3.0.lua
└── A
    ├── .1.0.lua
    └── 2.0.lua

$ module avail

 A/2.0 (D)

$ module --show_hidden avail

 .B/3.0 (H)    A/.1.0 (H)    A/2.0 (D)

It is also possible to mark modules with functions in modulerc files. See Site and user control of defaults, aliases and hidden modules for details on how to mark by using the modulerc files.

Remember that hidden modules can be loaded with normal commands unless its hidden type is hard.

Dot-leading version directories and LMOD_DOT_HIDDEN_LOAD_ALIAS

Background and rationale: GitHub issue #817.

When the version (or a path segment under the short name) begins with ., Lmod treats the module as hidden for avail and spider in the usual way (unless --show_hidden, --all, site policy, or hooks say otherwise). By default, loading uses the canonical name, including the dot: for example module load A/.1.0 loads A/.1.0.lua, while module load A/1.0 does not automatically pick A/.1.0.lua.

Sites may set the environment variable LMOD_DOT_HIDDEN_LOAD_ALIAS to yes (default is no) to opt in to an optional alias for loads:

• After an exact key lookup fails, Lmod may resolve a requested version string without dots (e.g. 1.2) to a single sibling modulefile whose path differs only by dot-leading segments (e.g. .1.2), iff that match is unique. If more than one filesystem key normalizes the same way, the alias is not applied (ambiguous).

• If both an undotted and a dotted key exist for the same logical version (for example pkg/1.2.lua and pkg/.1.2.lua), the exact undotted key wins; the alias is only for the case where the dotted layout is the sole match.

• Listing behavior is unchanged: hidden modules stay hidden from normal listings unless users or policy surface them as today.

When LMOD_DOT_HIDDEN_LOAD_ALIAS is yes and LMOD_PIN_VERSIONS is no, LOADEDMODULES records the logical loaded name (e.g. itk/1.2) while the module table still tracks the canonical fullName (e.g. itk/.1.2). With the alias off (the default), behavior matches prior releases for LOADEDMODULES.

Inside a modulefile, myModuleFullName() and myModuleVersion() report the true loaded name (including dot-leading segments). To obtain both the user’s requested name and the canonical name after an alias load, call myModuleUsrAndAliasName(); it returns two values. When no alias was used, both values are the same. For example, after module load itk/1.2 resolves to itk/.1.2.lua, myModuleUsrAndAliasName() returns itk/1.2 and itk/.1.2.

myModuleUsrAndAliasName() returns the user-typed name as its first value. That is appropriate for reporting what the user asked for, but it is not the right input for path construction on unload. For example, after module load hello loads hello/.1.0.lua, myModuleUsrName() is hello on unload, so a SitePackage.lua override that returns it from myModuleFullName() cannot extract a version and prepend_path may not be reversed correctly.

To obtain the logical full name and the true loaded full name, call myModuleFullNameAndAlias(). It returns two values. The first is the logical name (dot-leading segments stripped once per path segment). The second is the true loaded name (the same value myModuleFullName() returns). When no dot-leading segments are present, both values are the same.

Sites that want myModuleFullName() or myModuleVersion() to report the logical name when the true loaded name contains dot-leading segments may override those functions in SitePackage.lua via sandbox_registration. For example:

local orig_myModuleFullName = myModuleFullName
local orig_myModuleVersion  = myModuleVersion

local function myModuleFullName()
   local aliasFullName, trueFullName = myModuleFullNameAndAlias()
   if (aliasFullName == trueFullName) then
      return orig_myModuleFullName()
   end
   return aliasFullName
end

local function myModuleVersion()
   local full = myModuleFullName()
   local sn   = myModuleName()
   return extractVersion(full, sn) or ""
end

sandbox_registration{
   myModuleFullName  = myModuleFullName,
   myModuleVersion   = myModuleVersion,
}

Finally, if your site wishes to mark many modules as hidden, you can use the hook function isVisibleHook(). See SitePackage.lua and hooks for details. Also see the contrib/more_hooks/SitePackage.lua file for a worked example.