Can't install to prefix containing spaces

[krf]

./autogen.py -prefix "~/opt/kd reports"
-- Using source directory: /home/kfunk/devel/src/kdab/KDReports
-- Using repository information: revision=907e4c7c isTagged=False
-- Auto-generation done.
-- License marked as accepted.
-- Wrote build files to: /home/kfunk/devel/src/kdab/KDReports
-- Now running configure script.

KD Reports v1.7.50 configuration:
  Install Prefix.............: ~/opt/kd reports
    (default: /usr/local/KDAB/KDReports-1.7.50)
  Debug......................: no (default: no)
  Release....................: yes (default: yes)
  Shared build...............: yes (default: yes)
  Compiled-In Unit Tests.....: no (default: no)
  Restricted symbol export
    (shared build only)......: yes (default: yes)

Project MESSAGE: Install prefix is ~/opt/kd
Project MESSAGE: This is KD Reports version 1.7.50
Reading /home/kfunk/devel/src/kdab/KDReports/src/src.pro
Project MESSAGE: WARNING: kdchart not found. Please set KDCHARTDIR either as an environment variable or on the qmake command line if you want kdchart support
Reading /home/kfunk/devel/src/kdab/KDReports/examples/examples.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/tools/tools.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/Letter/Letter.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/HelloWorld/HelloWorld.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/ReferenceReport/ReferenceReport.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/PriceList/PriceList.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/Database/Database.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/HelloWorldXML/HelloWorldXML.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/PriceListXML/PriceListXML.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/DatabaseXML/DatabaseXML.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/LongReport/LongReport.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/LongTextReport/LongTextReport.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/BigImage/BigImage.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/MailMergeXML/MailMergeXML.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/ReportSection/ReportSection.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/examples/Labels/Labels.pro
Reading /home/kfunk/devel/src/kdab/KDReports/include/include.pro
 Reading /home/kfunk/devel/src/kdab/KDReports/include/KDReports/KDReports.pro
Cannot find file: reports.
qmake failed

Same for Windows. Same for all other KDAB products using autogen I presume.

This is a bug in the generated configure.{sh,bat}, using too simplistic command-line arg parsing.