<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi Armando,<div class="">Good to hear from you. I thought for a while that I had managed to fix it with the following code :</div><div class=""><br class=""></div><div class=""><div class=""> def main(filename=None):</div><div class=""> app = NXConsoleApp()</div><div class=""> app.initialize(filename=filename)</div><div class=""> app.start()</div><div class=""> for w in QApplication.topLevelWindows():</div><div class=""> del w</div><div class=""> del app.window, app.app</div><div class=""> sys.exit(0)</div><div class=""><br class=""></div><div class="">It proved to be a false dawn - the problem started to recur again. I’ll see if your version catches things that mine missed, and let you know.</div><div class=""><br class=""></div><div class="">I have spent a lot of time trying to cover up PyQt5 bugs in the past year. The problem is that I can’t guarantee that my users will have the latest version of PyQt, so even if it is fixed in v5.14, I still have to patch the code. I just have no idea why simply calling processEvents() triggers the bug. If I knew that, perhaps it would give some clue how to work around it.</div><div class=""><br class=""></div><div class="">Ray</div><div class=""><br class=""></div><div><br class=""><blockquote type="cite" class=""><div class="">On May 25, 2020, at 3:38 PM, V. Armando Sole <<a href="mailto:sole@esrf.fr" class="">sole@esrf.fr</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" class=""><div style="font-size: 10pt; font-family: Verdana,Geneva,sans-serif" class=""><p class="">Hi Ray,</p><p class="">I do not know if it will help your case. I was getting rid of some crashes on exit by deleting all widgets that had no parent. For instance, when closing the QMainWindow by doing:</p><p class=""> def closeEvent(self, event):<br class=""> if __name__ == "__main__":<br class=""> app = qt.QApplication.instance()<br class=""> allWidgets = app.allWidgets()<br class=""> for widget in allWidgets:<br class=""> try:<br class=""> # we cannot afford to crash here<br class=""> if id(widget) != id(self):<br class=""> if widget.parent() is None:<br class=""> widget.close()<br class=""> except:<br class=""> _logger.debug("Error closing widget")<br class=""> return qt.QMainWindow.closeEvent(self, event)</p><p class="">Best regards,</p><p class="">Armando</p><p class="">On 25.05.2020 19:48, Raymond Osborn wrote:</p>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0" class=""><!-- html ignored --><!-- head ignored --><!-- meta ignored -->I added a call to QtWidgets.QApplication.instance().processEvents() in order to force adjustResize() to work when switching tabs (that's another story). It succeeded in fixing my resize issue, but now it triggers a segfault when I exit the application. This seemed to be related to the bug described in <a href="https://www.riverbankcomputing.com/static/Docs/PyQt5/gotchas.html#crashes-on-exit" class="">https://www.riverbankcomputing.com/static/Docs/PyQt5/gotchas.html#crashes-on-exit</a>. One fix, suggested by @ekhumoro on stackoverflow (<a href="https://stackoverflow.com/questions/59120337/why-does-pyqt-sometimes-crash-on-exit" class="">https://stackoverflow.com/questions/59120337/why-does-pyqt-sometimes-crash-on-exit</a>) was to delete the main window and the app first, but that doesn't seem to fix it. I am running PyQt 5.12 because that is the last version supported by conda, so I can't test the one-exit fix in v5.13, and my users probably wouldn't have it installed anyway. It happens on Macs and linux.
<div class=""> </div>
<div class="">What I am asking is if there are additional things to try in addition to @ekhumoro's suggestion? Basically he suggests doing something like:</div>
<div class=""> </div>
<div class="">
<pre class="lang-py prettyprinted prettyprint" style="margin-top: 0px; margin-bottom: 1em; padding: 12px 8px; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-stretch: inherit; line-height: inherit; font-size: 13px; vertical-align: baseline; box-sizing: inherit; width: auto; max-height: 600px; overflow: auto; border-top-left-radius: 3px; border-top-right-radius: 3px; border-bottom-right-radius: 3px; border-bottom-left-radius: 3px; color: #242729; word-wrap: normal; caret-color: #242729;"><code style="margin: 0px; padding: 0px; border: 0px; font-family: Consolas, Menlo, Monaco, 'Lucida Console', 'Liberation Mono', 'DejaVu Sans Mono', 'Bitstream Vera Sans Mono', 'Courier New', monospace, sans-serif; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; white-space: inherit;" class=""><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--blue-800);">def</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);"> main</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">():</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
app </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">=</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: #2b91af;">QApplication</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">(</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">sys</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">.</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">argv</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">)</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
main_window </span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">=</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);"> </span><span class="typ" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: #2b91af;">MainWindow</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">()</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
main_window</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">.</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">show</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">()</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
app</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">.</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">exec_</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">()</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
</span><span class="com" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-400);"># ensure correct deletion order</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">
</span><span class="kwd" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--blue-800);">del</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);"> main_window</span><span class="pun" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);">,</span><span class="pln" style="margin: 0px; padding: 0px; border: 0px; font-family: inherit; font-style: inherit; font-variant-caps: inherit; font-stretch: inherit; line-height: inherit; vertical-align: baseline; box-sizing: inherit; color: var(--black-750);"> app</span></code></pre>
<div class="">Does anyone understand why the crash only occurs if I have calls to processEvents() in the code? It never happens when I remove them.</div>
</div>
<div class=""> </div>
<div class="">Thanks,</div>
<div class="">Ray</div>
<div class=""> </div>
<div class=""> </div>
</blockquote>
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