diff options
| -rw-r--r-- | doc/external-dependency-solver-protocol.txt | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/doc/external-dependency-solver-protocol.txt b/doc/external-dependency-solver-protocol.txt index e2bd95866..d914db309 100644 --- a/doc/external-dependency-solver-protocol.txt +++ b/doc/external-dependency-solver-protocol.txt @@ -263,11 +263,11 @@ the user. #### Solution -A solution is a list of Deb 822 stanzas. Each of them could be an -install stanza (telling APT to install a specific package), a remove -stanza (telling APT to remove one), or an autoremove stanza (telling APT -about the *future* possibility of removing a package using the -Autoremove action). +A solution is a list of Deb 822 stanzas. Each of them could be an install +stanza (telling APT to install a specific new package or to upgrade or +downgrade a package to a specific version), a remove stanza (telling APT to +remove one), or an autoremove stanza (telling APT about the *future* +possibility of removing a package using the Autoremove action). An **install stanza** starts with an Install field and supports the following fields: @@ -289,6 +289,11 @@ this protocol makes no assumption on the fact that a subsequent invocation of an Autoremove action will actually remove the very same packages indicated by Autoremove stanzas in the former solution. +The package identifiers of install, remove and autoremove stanzas from a single +solution are unique. That is, a package identifier does not occur more than +once in the solution. Every package identifier is only associated with a single +action (either install, remove or autoremove). + In terms of expressivity, install and remove stanzas can carry one single field each, as APT-IDs are enough to pinpoint packages to be installed/removed. Nonetheless, for protocol readability, it is |