Advanced module version specifiers

Configuration

  • Introduce advanced_version_spec option name

    • off by default in v4 as previously soft@1 could be a module name

    • on by default in v5

    • in case extended_default is disabled

      • means short-hand notation cannot be used

        • for soft/1.1 query soft@1 returns nothing

    • in case implicit_default is disabled

      • means a default should be found over version range or list in selection context

Specification

  • Following Spack spec

  • same grammar used whatever the context

    • command-line or as argument to modulefile command (like command)

  • versions are specified whether

    • as specific words (separated by " ")

    • or as suffix to module name

  • change command specifications which were previously accepting list of modules

    • like module1 module2/vers module3

    • now these modules could express versions appended to their name with @

      • like module1@1.8 module2@vers module3

    • or these versions could be defined as words next to module name

      • like module1@1.8 module2 @vers module3

    • as a consequence, it denies use of @ in module names

    • such change requires an option to be enabled to avoid breaking compat

  • single version could be specified with soft@vers

    • which matches soft/vers modulefile

  • version could be specified as range

    • soft@:vers or soft@vers: or soft@vers1:vers2

    • Tcl-dictionarily determine what is between specified range

    • extended_default is always considered on when matching range

      • as 2.10 is included in @1:3 whatever the configuration

    • to be specified in a range or compared to a range, version major element should match an hexadecimal number

      • which also means be only composed by [0-9af] characters

      • for instance 10a, 1.2.3, 1.foo, 10.2.good are versions valid for range comparison

      • but 10g, default, foo.2, .1.3.4 are versions invalid for range comparison

    • a version range using in its definition version invalid for range comparison raises error

      • for instance @bar:foo

    • existing module versions invalid for range comparison are ignored

      • which means versions 10g, default, .1.13.4 or new are excluded from result for a @1.10: range query

    • when range is defined as @major:major.minor, version matching major version but above major.minor are excluded

      • for instance @1:1.10 will matches 1.0 and 1.8 but not 1.12

  • version could be specified as list

    • soft@vers,vers,vers

    • version specified could be text, like if symbolic version names are used

    • should benefit from extended default specification

      • to just express version with their major release number for instance

    • an empty string among list is considered as a specification error

      • for instance soft@vers,vers, or soft@vers,,vers

    • any version in list can be a single version or a version range

      • like soft@1.2,1.4:1.6,1.8

      • helps to designate all versions except a few ones

  • when using extended default syntax

    • version selection is performed same way for @vers than for /vers

    • described in extended default design

  • when icase is enabled for selection context and multiple directories match module name

    • for instance query is ICase@1.1,1.2,1.4 and following modules exist: ICASE/1.1, icase/1.2, iCaSe/1.3 and iCaSe/1.4

    • as no ICase directory exists, and a version in highest directory icase matches query (1.2), icase/1.2 is returned

    • if query is iCaSe@1.1,1.2,1.4, iCaSe/1.4 will be selected as iCaSe directory matches query module name

    • if query is ICase@1.1,1.4 or icase@1.1,1.4, as no version match in highest directory iCaSe/1.4 will be selected

  • in case of deep modulefiles

    • specified version is matched at the level directly under specified module name

      • not below levels

      • for instance soft@vers, will match soft/vers, not soft/deep/vers

      • to specify version for deep modules:"soft/deep@vers

      • to ease version comparison deep version cannot be specified after the @ character like soft@deep/vers

        • such specification will raise an error

  • advanced version specifier cannot be used with full path modulefile

    • when a full path modulefile is specified any advanced version set afterward is treated literally

    • for instance /path/to/modulefiles/mymod@1.2 will lead to the access of file mymod@1.2 in directory /path/to/modulefiles

  • in case version is specified multiple times

    • lastly mentioned (read from left to right) value is retained (it overwrite previous values)

    • like module@1.8 @2.0 or module@1.8@2.0

    • beware of version specified over a fully qualified modulefile like in soft/1.8@1.10" or "soft/1.8 @1.10

      • it resolves to soft/1.8/1.10 as advanced version specified is treated as an additional directory level

  • in case modulefile is named module@vers in filesystem

    • it is not found when option advanced_version_spec is enabled

    • as it is translated to module/vers

  • when special characters like ? or * are used in version name or value

    • they are evaluated as Tcl glob pattern on return all matching modules context

    • they are treated literally on single module selection and compatibility check context, no wildcard meaning is applied

    • like currently done when specifying module version on command-line

      • which leads to errors as no corresponding module is found:

        $ module load loc_dv6/*
ERROR: Unable to locate a modulefile for 'loc_dv6/*'

  • if version range or list does not contain a defined default

    • in a selection context

      • highest version is returned if implicit_default is enabled

      • error returned if implicit_default is disabled

        • even if version range or list specifies non-existent modules and only one existent module

    • in a compatibility expression context

      • range or list is matched against loaded environment whether the implicit_default state

      • when no match found and evaluation are triggered, selection context applies

  • when version is specified over an alias

    • should proceed like for real modulefile

    • when alias equal to a bare module with no version

      • foo is alias on bar modulefile, bar is a file (not a dir with version modulefiles)

      • query alias@:2 should behave like query alias/2

    • when alias equal to a module/version modulefile

      • foo is alias on bar/3 modulefile

      • query alias@:2 should behave like query alias/2

  • Contexts where it could be used

Note

Advanced version specifier does not apply for the moment to the Module identification to select one module context. Adding support for this context will require a significant rework on module alias and symbolic version registering and resolving code.

  • impact of advanced version specifier implementation over code

    • question especially over auto_handling code like conflict and prereq handling

    • it should not impact triggers and actions

    • but consist in an overall change of procedures comparing queries against loaded environment

      • procedures like doesModuleConflict

    • also adapting getModules to restrict version possibilities to what has been specified

      • for instance with query soft@1,2 should only return versions matching

  • prereq/conflict persistency

    • LMPREREQ and LMCONFLICT content should reflect specified version constraint

    • it could be expressed in these variables somewhat like it is specified to the

      • prereq/conflict modulefile commands

      • for instance __MODULES_LMPREREQ=soft/1.10&bar@1.8,1.10&foo@<2|foo@3<4

      • delimiters characters are :, & and |

        • so use of characters * , *@, , is not an issue

        • but for : which express version ranges it should be substituted to <

  • prereq/conflict specification

    • could consolidate different version set for same module on the same prereq/conflict list

      • to indicate a preferred order (if available)

      • like prereq foo@1.8 foo@1.10

      • or prereq foo @1.8 foo@1.10

    • also to trigger alternative requirement resolution in case first one failed

      • as each module version specification leads to one evaluation only

        • even if multiple modulefiles correspond to this specification

          • like prereq soft@1.8,1.9,1.10 will lead to soft/1.10 load

        • best candidate is chosen from matches

          • in case implicit_default is disabled an explicit default should be part of the list or range for the triggered evaluation to succeed

      • whereas prereq soft@1.8 soft@1.9 soft@1.10 will lead to a tentative load

        • of soft/1.8, then soft/1.9 if it failed then soft/1.8 if it also failed

    • one module version specification may match multiple loaded modules

      • like conflict soft@1.8,1.9,1.10 matches loaded modules soft/1.8 and soft/1.10

      • similar to situations where requirement or conflict is expressed over module generic name, like soft, and multiple versions of module are loaded

Corner cases

  • When icase is enabled on all contexts and multiple directories match same icase module name

    • for instance following modules exist: ICASE/1.1, icase/1.2, iCaSe/1.3 and iCaSe/1.4

    • a module avail -i icase will sort iCaSe/1.4 as the highest entry

    • however a module load -i icase@1.1,1.2,1.4 command will load icase/1.2

      • as icase directory matches query and version 1.2 is found in icase directory

    • but a module load -i icase@1.1,1.4 command will load iCaSe/1.4

      • as no version 1.1 nor 1.4 is found in icase directory