tests: do not hard code HTTP ports

Previously, test cases could fail if some process was listening
at a hard-coded port.  This patch eliminates most of these potential
failures, by automatically assigning an unbound port.  This should
allow for building multiple guix trees in parallel outside a build
container, though this is currently untested.

The test "home-page: Connection refused" in tests/lint.scm still
hardcodes port 9999, however.

* guix/tests/http.scm
  (http-server-can-listen?): remove now unused procedure.
  (%http-server-port): default to port 0, meaning the OS
  will automatically choose a port.
  (open-http-server-socket): remove the false statement claiming
  this procedure is exported and also return the allocated port
  number.
  (%local-url): raise an error if the port is obviously unbound.
  (call-with-http-server): set %http-server-port to the allocated
  port while the thunk is called.
* tests/derivations.scm: adjust test cases to use automatically
  assign a port.  As there is no risk of a port conflict now,
  do not make any tests conditional upon 'http-server-can-listen?'
  anymore.
* tests/elpa.scm: likewise.
* tests/lint.scm: likewise, and add a TODO comment about a port
  that is still hard-coded.
* tests/texlive.scm: likewise.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

1 files changed, 0 insertions, 3 deletions

diff --git a/tests/texlive.scm b/tests/texlive.scm
index f7e5515c4c..a6f08046a8 100644
--- a/tests/texlive.scm
+++ b/tests/texlive.scm
@@ -69,9 +69,6 @@
                  (keyval (@ (value "tests") (key "topic")))
                  "\n  null\n")))
 
-;; Avoid collisions with other tests.
-(%http-server-port 10200)
-
 (test-equal "fetch-sxml: returns SXML for valid XML"
   sxml
   (with-http-server `((200 ,xml))